Editorial

6 pages, 192 KiB

Open AccessEditorial

Green Separation and Extraction Processes: Part I

by George Z. Kyzas and Kostas A. Matis

Processes 2020, 8(3), 374; https://doi.org/10.3390/pr8030374 - 23 Mar 2020

Cited by 1 | Viewed by 2496

Supercritical fluid extraction comprises a known technology applied to obtain volatile compounds from flowers, i [...] Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

Research

Jump to: Editorial, Review, Other

11 pages, 1289 KiB

Open AccessArticle

Fractionating of Lemongrass (Cymbopogon citratus) Essential Oil by Vacuum Fractional Distillation

by Dinh Nhat Do, Dinh Phuc Nguyen, Viet-Duc Phung, Xuan-Tien Le, Tuan Minh Le, Van Manh Do, Bui Quang Minh and Xuan Cuong Luu

Processes 2021, 9(4), 593; https://doi.org/10.3390/pr9040593 - 29 Mar 2021

Cited by 22 | Viewed by 9698

Abstract

Lemongrass essential oil has many compounds appropriate for application in foods, cosmetics, and pharmaceutical products. Of these, citral is a high-value compound of interest to industry. This work aims to evaluate the use of vacuum fractional distillation to separate lemongrass essential oil compounds, [...] Read more.

Lemongrass essential oil has many compounds appropriate for application in foods, cosmetics, and pharmaceutical products. Of these, citral is a high-value compound of interest to industry. This work aims to evaluate the use of vacuum fractional distillation to separate lemongrass essential oil compounds, producing essential oil fractions containing high citral content. The effect of process parameters, namely vacuum pressure, type column, and energy input, on the fractionation time, content, and recovery of citral in the fractions, was investigated. The fractionation of lemongrass oils successfully provided five fractions, i.e., fraction 1 (F1), fraction 2 (F2), fraction 3 (F3), fraction 4 (F4), and fraction 5 (F5). GC-MS (Gas Chromatography-Mass Spectrometry) spectra showed that the main compound contained in F1 and F2 fractions was β-myrcene (>70%). Meanwhile, F4 and F5 were the two main fractions for citral recovery. The optimal conditions of the fractional distillation system included a column height of 400 mm, power input of 165 W, and pressure of 15 mmHg. These conditions correspond to the highest total citral content of 95%, with a recovery of 80% at the F4 and F5 fractions. Therefore, fractional vacuum distillation may be an effective method to upgrade lemongrass essential oil. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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10 pages, 1394 KiB

Open AccessArticle

Optimization and Validation of an Extraction Method for Endosulfan Lactone on a Solid Substrate

by Paola T. Vázquez-Villegas, Rocío Meza-Gordillo, María C. Luján-Hidalgo, Abumalé Cruz-Salomón, Víctor M. Ruíz-Valdiviezo, Federico A. Gutiérrez-Miceli, Juan J. Villalobos-Maldonado and Joaquín A. Montes-Molina

Processes 2021, 9(2), 284; https://doi.org/10.3390/pr9020284 - 02 Feb 2021

Cited by 4 | Viewed by 2311

Abstract

Endosulfan lactone is a metabolite obtained from the biological oxidation of the insecticide endosulfan by action of the microorganisms present in the soil. This metabolite is more toxic and persistent than the parent compound. Therefore, it is extremely important to be able to [...] Read more.

Endosulfan lactone is a metabolite obtained from the biological oxidation of the insecticide endosulfan by action of the microorganisms present in the soil. This metabolite is more toxic and persistent than the parent compound. Therefore, it is extremely important to be able to determine the presence of this metabolite in the soil. However, accessible methods for extraction of endosulfan lactone in soil were not found in published literature. For this reason, the aim of this study was to evaluate two conventional methods of liquid–solid extraction for the determination of endosulfan lactone in solid substrate using two solvents (ethyl acetate and acetonitrile) and HPLC UV-VIS. The acetonitrile and rotary agitation extraction method was the one with the highest efficiency (97%), optimized using a factorial 3² response surface design, and validated in terms of linearity and precision. The linearity shown was r > 0.999 in a wide spike level (0.15–100 mg kg⁻¹), with the detection limit (DL) of 0.045 mg kg⁻¹ and quantification limit (QL) of 0.15 mg kg⁻¹. The extraction of endosulfan lactone in solid substrate using acetonitrile was more efficient than that used with ethyl acetate, so this method could be used to extract and quantify endosulfan lactone in agricultural soil. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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21 pages, 4187 KiB

Open AccessArticle

Alcohol Dehydration by Extractive Distillation with Use of Aminoethers of Boric Acid

by Alexander V. Klinov, Alexander V. Malygin, Alina R. Khairullina, Sergey E. Dulmaev and Ilsiya M. Davletbaeva

Processes 2020, 8(11), 1466; https://doi.org/10.3390/pr8111466 - 16 Nov 2020

Cited by 7 | Viewed by 2825

Abstract

Aminoethers of boric acid (AEBA) were studied as potential extractants for the separation of aqueous–alcoholic azeotropic mixtures by extractive distillation. The conditions of vapor–liquid equilibrium in aqueous solutions of ethanol and isopropanol in the presence of AEBA were studied. The division of AEBA [...] Read more.

Aminoethers of boric acid (AEBA) were studied as potential extractants for the separation of aqueous–alcoholic azeotropic mixtures by extractive distillation. The conditions of vapor–liquid equilibrium in aqueous solutions of ethanol and isopropanol in the presence of AEBA were studied. The division of AEBA molecules into group components was proposed, and previously unknown geometric parameters of the boron group and the energetic pair parameters of the boron group with the alkane group, ether group, amine-3d group, and alcohol group were determined within the framework of the Universal Functional Group Activity Coefficient (UNIFAC) model. The modeling of the extractive rectification process of an ethanol–water mixture with AEBA as extractant has been carried out. The dependences of the cost function on the extractant flow rate, the residual water content in it and the number of theoretical trays were obtained. A technological scheme for ethanol dehydration has been proposed, and its technological characteristics have been calculated. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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13 pages, 1888 KiB

Open AccessArticle

Optimization of Extrusion and Ultrasound-Assisted Extraction of Phenolic Compounds from Jizi439 Black Wheat Bran

by Xi Chen, Xinyue Li, Xiangwei Zhu, Guozhen Wang, Kun Zhuang, Yuehui Wang and Wenping Ding

Processes 2020, 8(9), 1153; https://doi.org/10.3390/pr8091153 - 15 Sep 2020

Cited by 9 | Viewed by 2533

Abstract

Jizi439, a newly developed black wheat breeding line, was reported to effectively regulate blood glucose, which may potentially be associated with its intrinsic high level of phenolic compounds (PCs). To maximize the PCs yield and thereby enhance their antioxidant activity, orthogonal experiments were [...] Read more.

Jizi439, a newly developed black wheat breeding line, was reported to effectively regulate blood glucose, which may potentially be associated with its intrinsic high level of phenolic compounds (PCs). To maximize the PCs yield and thereby enhance their antioxidant activity, orthogonal experiments were designed in sequence for extrusion of Jizi439 black wheat bran (BWB) powder and followed by the extraction of PCs assisted with ultrasound technique. White wheat bran was used as a control. The optimum condition for extrusion was 110 °C, 25% feed water content, 140 rpm screw speed; meanwhile, 50 °C, 40 min, 35 kHz ultrasonic frequency, 300 W ultrasonic power for ultrasound-assisted extraction (UAE). Total phenolic content (TPC) as determined by Folin–Ciocalteu method was 2856.3 ± 57.7 μg gallic acid equivalents (GAE) per gram of dry weight (DW) of phenolic extract; meanwhile, antioxidant activity (AA) in terms of DPPH radical scavenging ratio was 85.5% ± 1.1% under optimized conditions, which were both significantly higher than the control. Phenolic acids except for gallic acid, as well as flavonoids, including luteolin and apigenin were increased by extrusion and ultrasound, as suggested by HPLC results. In conclusion, our study would provide a valuable reference for processing Jizi439 BWB before making or commercially utilize it into health-related food products. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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16 pages, 8763 KiB

Open AccessArticle

Eucalyptus camaldulensis, Citrus aurantium, and Citrus sinensis Essential Oils as Antifungal Activity against Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Fusarium culmorum

by Wael A.A. Abo Elgat, Ahmed M. Kordy, Martin Böhm, Robert Černý, Ahmed Abdel-Megeed and Mohamed Z.M. Salem

Processes 2020, 8(8), 1003; https://doi.org/10.3390/pr8081003 - 18 Aug 2020

Cited by 30 | Viewed by 7136

Abstract

Several molds are able to colonize wood and many building products or solid wood causing losses for their valuable uses. Essential oils (EOs) from aromatic plants can be used as an ecofriendly biofungicide against the growth of several molds. EOs from Eucalyptus camaldulensis [...] Read more.

Several molds are able to colonize wood and many building products or solid wood causing losses for their valuable uses. Essential oils (EOs) from aromatic plants can be used as an ecofriendly biofungicide against the growth of several molds. EOs from Eucalyptus camaldulensis, Citrus aurantium, and C. sinensis have a broad-spectrum antimicrobial activity. EOs from of E. camaldulensis air-dried aerial parts, C. aurantium leaf and C. sinensis peel, and their combinations (1:1 v/v) were evaluated for their antifungal activity against the growth of four common mold fungi (Aspergillus flavus, A. niger, A. terreus, and Fusarium culmorum). The chemical compositions of the EOs were analyzed with GC/MS. The main compounds in EO from E. camaldulensis were spathulenol (20.84%), eucalyptol (12.01%), and sabinene (9.73%); in C. aurantium were linalyl acetate (42.29%), and linalool (29.76%); and in C. sinensis were D-limonene (73.4%) and γ-terpinene (22.6%). At 50 µL/mL, C. sinensis EO showed the highest fungal mycilial growth inhibition (FMGI) percentage (86.66%) against A. flavus. C. sinensis, E. camaldulensis, and E. camaldulensis/C. sinensis showed FMGI values of 96%, 91.66%, and 75.66% respectively, against A. niger. EOs from C. aurantium and C. sinensis showed potent activity against A. terreus (100% FMGI), while C. aurantium/E. camaldulensis and E. camaldulensis/C. sinensis showed FMGI values of 74.33% and 70.66%, respectively. Potent activity against F. culmorum with 100% was observed as the application of E. camaldulensis and C. sinensis EOs at 50 µL/mL, while E. camaldulensis/C. sinensis (50 µL/mL) showed FMGI value of 65.66%. The results suggest using the EOs and their combinations from E.camaldulensis, C. aurantium, and C. sinensis as a biofungicide against molds. The potent properties of EOs offer the possibility of using them as eco-friendly, safe, and cost-effective antimicrobials for molds that could cause discoloration of the wood packaging or food spoilage. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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10 pages, 2688 KiB

Open AccessArticle

Process Optimization for Green Synthesis of Silver Nanoparticles Using Indonesian Medicinal Plant Extracts

by Kartini Kartini, Amarisa Alviani, Dia Anjarwati, Adinda Finna Fanany, Johan Sukweenadhi and Christina Avanti

Processes 2020, 8(8), 998; https://doi.org/10.3390/pr8080998 - 17 Aug 2020

Cited by 17 | Viewed by 5040

Abstract

Silver nanoparticles (AgNPs) are an interesting metal nanoparticle that can be incorporated into pharmaceutical products, including for diabetic foot ulcers as an antimicrobial agent. Green synthesis of AgNPs using plant extracts has been drawing much attention as it is simple, eco-friendly, stable, and [...] Read more.

Silver nanoparticles (AgNPs) are an interesting metal nanoparticle that can be incorporated into pharmaceutical products, including for diabetic foot ulcers as an antimicrobial agent. Green synthesis of AgNPs using plant extracts has been drawing much attention as it is simple, eco-friendly, stable, and cost-effective. This present study was performed to evaluate the potential of three Indonesian medicinal plant extracts, namely Phyllanthus niruri (PN), Orthosiphon stamineus (OS), and Curcuma longa (CL), as reducing and capping agents in the green synthesis of AgNPs, and to optimize their concentrations. Based on the yields and characteristics of the formed nanoparticles, which were analyzed using a UV-Vis spectrophotometer, particle size analyzer, scanning electron microscope, and X-ray diffractometer, Phyllanthus niruri extract at a concentration of 0.5% was concluded as the best extract in the green synthesis of AgNPs. It is thereby a prospective reducing and capping agent for further scale-up studies. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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19 pages, 2376 KiB

Open AccessArticle

Analysis and Prediction of Influencing Parameters on the Coal Classification Performance of a Novel Three Products Hydrocyclone Screen (TPHS) Based on Grey System Theory

by Chuanzhen Wang, Xiaolu Sun, Liang Shen and Guanghui Wang

Processes 2020, 8(8), 974; https://doi.org/10.3390/pr8080974 - 12 Aug 2020

Cited by 8 | Viewed by 4474

Abstract

A novel hydrocyclone including a cylindrical screen embedded in a conventional hydrocyclone (CH), named three products hydrocyclone screen (TPHS), has been successfully designed. In TPHS, the combination of centrifugal classification and screening was employed to separate particles. In this paper, Grey theory, as [...] Read more.

A novel hydrocyclone including a cylindrical screen embedded in a conventional hydrocyclone (CH), named three products hydrocyclone screen (TPHS), has been successfully designed. In TPHS, the combination of centrifugal classification and screening was employed to separate particles. In this paper, Grey theory, as an effective means to the laws of both complex and uncertainty system’s behavior with small samples, was used to investigate the operational (feed concentration and feed pressure) and structural (aperture size, spigot diameter, and vortex finder diameter) parameters on performance evaluation Hancock classification efficiency (HE), imperfection (I), and cut size (d_50c). The experiments of coal sample (0–1 mm) show that TPHS with coarser particles in underflow exhibited the absent “fish-hook”. The closeness calculated using the Grey System algorithm indicates that the performance of TPHS was closely related to the operation and structure parameters. Further, the order of grey incidence degree between different parameters and HE (or I or d_50c) is the spigot diameter and aperture size with the highest value, the feed pressure and vortex finder diameter with the middle value, and the feed concentration with the lowest value. The prediction using the GM(1, N) algorithm implies that the dynamic prediction model for the performance evaluation can be created depending on the operation, structure and previous performance value. The mean relative errors between the predicted and actual HE, I, and d₅₀ were 2.84%, 5.83%, and 3.57%, respectively, which exhibit the accurate prediction. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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16 pages, 3760 KiB

Open AccessArticle

Extraction of Phosphorous from a Phosphorous-Containing Vanadium Titano-Magnetite Tailings by Direct Flotation

by Junhui Xiao, Chao Chen, Wei Ding, Yang Peng, Tao Chen and Kai Zou

Processes 2020, 8(7), 874; https://doi.org/10.3390/pr8070874 - 20 Jul 2020

Cited by 4 | Viewed by 3749

Abstract

In this study, there is 1.42% P₂O₅ in the P-containing V-Ti magnetite tailings in Miyi Region of China, with the valuable minerals mainly including apatite, and aluminosilicate minerals as the main gangue components. The direction flotation process was used to [...] Read more.

In this study, there is 1.42% P₂O₅ in the P-containing V-Ti magnetite tailings in Miyi Region of China, with the valuable minerals mainly including apatite, and aluminosilicate minerals as the main gangue components. The direction flotation process was used to recover phosphorous from the low-grade phosphorous-bearing V-Ti magnetite tailings. The results showed that an optimized phosphorous concentrate with a P₂O₅ grade of 31.35% and P₂O₅ recovery of 88.02% was obtained by flotation process of one roughing, three scavengings, and three cleanings under roughing conditions, which employed pulp pH of 9, grinding fineness of <0.039 mm occupying 90%, flotation concentration of 25%, and dosages of carboxymethylcellulose, oxidized paraffin wax soap, and pine oil of 400 g/t, 300 g/t, and 20 g/t, respectively. Optimized one scavenging, two scavenging, and three scavenging conditions used a pulp pH of 9, and dosages of carboxymethylcellulose, oxidized paraffin wax soap, and pine oil of 200 g/t, 150 g/t, 10 g/t; 100 g/t, 75 g/t, and 5 g/t; and 100 g/t, 75 g/t, and 5 g/t, respectively. Optimized one cleaning, two cleaning, and three cleaning condition dosages of carboxymethylcellulose of 100 g/t, 50 g/t, and 25 g/t, respectively. Study of analysis and characterization of phosphorous concentrate by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) show that most gangue minerals enter the flotation tailings, the main minerals in phosphorous concentrate are apatite, olivine, and feldspar. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 3735 KiB

Open AccessArticle

Organoboron Ionic Liquids as Extractants for Distillation Process of Binary Ethanol + Water Mixtures

by Ilsiya M. Davletbaeva, Alexander V. Klinov, Alina R. Khairullina, Alexander V. Malygin, Sergey E. Dulmaev, Alisa R. Davletbaeva and Timur A. Mukhametzyanov

Processes 2020, 8(5), 628; https://doi.org/10.3390/pr8050628 - 24 May 2020

Cited by 9 | Viewed by 3198

Abstract

Aminoethers of boric acid, which are organoboron ionic liquids, were synthesized by using boric acid, triethanolamine, and triethylene glycol/diethylene glycol. Due to the formation of intermolecular complexes of borates, the structure of aminoethers of boric acid contains ion pairs separated in space, giving [...] Read more.

Aminoethers of boric acid, which are organoboron ionic liquids, were synthesized by using boric acid, triethanolamine, and triethylene glycol/diethylene glycol. Due to the formation of intermolecular complexes of borates, the structure of aminoethers of boric acid contains ion pairs separated in space, giving these compounds the properties inherent to ionic liquids. It is established that the thermal stability of aminoethers under normal atmospheric conditions increases with an increase in the size of the glycol. According to measurements of fast scanning calorimetry, density, dynamic viscosity, and electrical conductivity, water is involved in the structural organization of aminoethers of boric acid. The impact of the most thermostable organoboron ionic liquids on the phase equilibrium conditions of the vapor–liquid azeotropic ethanol–water mixture is studied. It is shown that the presence of these substances leads to increase in the relative volatility of ethanol. In general, the magnitude of this effect is at the level shown by imidazole ionic liquids, which provide high selectivity in the separation of aqueous alcohol solutions. A large separation factor, high resistance to thermal oxidative degradation processes, accompanied by low cost start reagents, make aminoethers of boric acid on the basis of triethylene glycol a potentially effective extractant for the extractive distillation of water–alcohol mixtures. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 1356 KiB

Open AccessArticle

Deacidification of Palm Oil Using Betaine Monohydrate-Carboxylic Acid Deep Eutectic Solvents: Combined Extraction and Simple Solvent Recovery

by Kamarza Mulia, Mohammad Nasikin, Elsa Anisa Krisanti and Ida Zahrina

Processes 2020, 8(5), 543; https://doi.org/10.3390/pr8050543 - 07 May 2020

Cited by 8 | Viewed by 4537

Abstract

Steam stripping is commonly used to remove free fatty acids from crude palm oil. An alternative deacidification method, solvent extraction performed at a much lower temperature, would preserve the natural antioxidants in the refined palm oil. In this work, palmitic acid was extracted [...] Read more.

Steam stripping is commonly used to remove free fatty acids from crude palm oil. An alternative deacidification method, solvent extraction performed at a much lower temperature, would preserve the natural antioxidants in the refined palm oil. In this work, palmitic acid was extracted using betaine monohydrate-propionic acid and betaine monohydrate-acetic acid deep eutectic solvents (DESs). The effect of temperature (40 °C to 80 °C), mass ratio of palm oil to solvent (2:1 to 1:2), and palmitic acid content in the palm oil feed (2% to 8% mass) on the distribution coefficient values of palmitic acid (0.44–0.93) was investigated. For the first time, a facile recovery of DESs could be accomplished by a cooling process where up to 98% of the palmitic acid separates as solid. A solvent extraction process for palm oil deacidification, employing a DES with a distribution coefficient value much higher than unity, will provide advantages over the steam stripping process. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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16 pages, 652 KiB

Open AccessArticle

Bioactivity of Selected Phenolic Acids and Hexane Extracts from Bougainvilla spectabilis and Citharexylum spinosum on the Growth of Pectobacterium carotovorum and Dickeya solani Bacteria: An Opportunity to Save the Environment

by Nader A. Ashmawy, Said I. Behiry, Asma A. Al-Huqail, Hayssam M. Ali and Mohamed Z. M. Salem

Processes 2020, 8(4), 482; https://doi.org/10.3390/pr8040482 - 21 Apr 2020

Cited by 24 | Viewed by 4024

Abstract

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft [...] Read more.

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft rot bacterial isolates and were initially identified through morphological, physiological, and pathogenicity tests. The molecular characterization of these isolates via PCR, based on the 16S rRNA region, was carried out by an analysis of the DNA sequence via BLAST and Genbank, and showed that the soft rot bacterial isolates belong to Pectobacterium carotovorum subsp. carotovorum (PCC1) and Dickeya solani (Ds1). The in vitro results of the tested phenolic acids against the cultured bacterial isolates proved that concentrations of 800, 1600, and 3200 μg/mL were the most effective. Ferulic acid was the potent suppressive phenolic acid tested against the Ds1 isolate, with an inhibition zone ranging from 6.00 to 25.75 mm at different concentrations (25–3200 μg/mL), but had no effect until reaching a concentration of 100 μg/mL in the PCC1 isolate, followed by tannic acid, which ranged from 7.00 to 25.50 mm. On the other hand, tannic acid resulted in a significant decrease in the growth rate of the PCC1 isolate with a mean of 9.11 mm. Chlorogenic acid was not as effective as the rest of the phenolic acids compared with the control. The n-hexane oily extract (HeOE) from Bougainvillea spectabilis bark showed the highest activity against PCC1 and Ds1, with inhibition zone values of 12 and 12.33 mm, respectively, at a concentration of 4000 μg/mL; while the HeOE from Citharexylum spinosum wood showed less activity. In the GC/MS analysis, nonanal, an oily liquid compound, was found ata percentage of 38.28%, followed by cis-2-nonenal (9.75%), which are the main compounds in B. spectabilis bark HeOE, and 2-undecenal (22.39%), trans-2-decenal (18.74%), and oleic acid (10.85%) were found, which are the main compounds in C. spinosum wood HeOE. In conclusion, the phenolic acids and plant HeOEs seem to raise the resistance of potato plants, improving their defense mechanisms against soft rot bacterial pathogens. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 3720 KiB

Open AccessArticle

Recovering Scandium from Scandium Rough Concentrate Using Roasting-Hydrolysis-Leaching Process

by Junhui Xiao, Yang Peng, Wei Ding, Tao Chen, Kai Zou and Zhen Wang

Processes 2020, 8(3), 365; https://doi.org/10.3390/pr8030365 - 22 Mar 2020

Cited by 17 | Viewed by 4505

Abstract

In this study, a roasting-hydrolysis-acid leaching process is used to extract scandium from the scandium rough concentrate. The scandium rough concentrate containing Sc₂O₃ of 76.98 g/t was obtained by magnetic separation, gravity separation, and electric separation from Sc-bearing Vi-Ti magnetite [...] Read more.

In this study, a roasting-hydrolysis-acid leaching process is used to extract scandium from the scandium rough concentrate. The scandium rough concentrate containing Sc₂O₃ of 76.98 g/t was obtained by magnetic separation, gravity separation, and electric separation from Sc-bearing Vi-Ti magnetite tailings in the Panxi area of China. The majority of scandium in scandium rough concentrate mainly occurs in diopside, titanopyroxene, montmorillonite, chlorite, talc, aluminosilicate minerals, and isomorphism. Sodium salt and scandium coarse concentrate are added into the roasting furnace for roasting, which makes the fusion reaction of silicon, aluminum and sodium salt to produce soluble salts such as sodium silicate and sodium metaaluminate. Scandium is further recovered from the hydrolysis residue by acid leaching. Test results show scandium leaching recovery of 95.12% and the acid leaching residue with Sc₂O₃ content of 8.12 g/t are obtained, while the extraction of scandium is obvious. There is no obvious peak value of Scandium spectrum in hydrochloric acid leach residue. Most of scandium in hydrolytic residue is dissolved into Sc³⁺ and enters into the liquid phase. The main minerals in leach residue are perovskite, ferric silicate, and olivine. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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18 pages, 3969 KiB

Open AccessArticle

Phytochemical Compounds of Branches from P. halepensis Oily Liquid Extract and S. terebinthifolius Essential Oil and Their Potential Antifungal Activity

by Abeer A. Mohamed, Said I. Behiry, Hayssam M. Ali, Mervat EL-Hefny, Mohamed Z.M. Salem and Nader A. Ashmawy

Processes 2020, 8(3), 330; https://doi.org/10.3390/pr8030330 - 11 Mar 2020

Cited by 40 | Viewed by 3669

Abstract

In the present study, the antifungal activity of wood treated with Pinus halepensis branch n-hexane oily liquid extract (OLE) and Schinus terebinthifolius branch essential oil (EO) was evaluated against the growth of four phytopathogenic fungi—Bipolaris oryzae, Fusarium oxysporum, Fusarium solani, [...] Read more.

In the present study, the antifungal activity of wood treated with Pinus halepensis branch n-hexane oily liquid extract (OLE) and Schinus terebinthifolius branch essential oil (EO) was evaluated against the growth of four phytopathogenic fungi—Bipolaris oryzae, Fusarium oxysporum, Fusarium solani, and Rhizoctonia solani. Air-dried wood samples of Pinus roxburghii were autoclaved, and each wood received 100 µL of the concentrated oils from P. halepensis and S. terebinthifolius. The main compounds identified in S. terebinthifolius branch EO were terpinen-4-ol (18.25%), cis-β-terpineol (15.60%), γ-terpinene (12.46%), sabinene (9.83%), α-terpinene (8.56%), and 4-thujanol (6.71%), while the main compounds in P. halepensis branch HeO were 2-undecenal (22.25%), 4-hydroxy-10-methyl-3,4,7,8,9,10-hexahydro-2H-oxecin-2-one (8.43%), (Z)-2-decenal (6.88%), nonanal (5.85%), (2E)-2-decenal (4.65%), (E,E)-2,4-decadienal (4.41%), arachidonic acid methyl ester (4.36%), and 2-(7-heptadecynyloxy)tetrahydro-2H-pyran (4.22%). P. halepensis OLE at a concentration of 3% showed the highest inhibition percentage of fungal growth (IPFG) of B. oryzae, followed by S. terebinthifolius EO at 3% and 2%, with IPFG values of 80%, 74.44%, and 71.66%, respectively. At a concentration of 3%, branch oils from S. terebinthifolius and P. halepensis were found to have the highest IPFG values with 45.55% and 40.55%, respectively, against F. oxysporum growth. Moderate to weak activity was found against F. solani when S. terebinthifolius EO and P. halepensis OLE were applied to wood. EO and OLE-treated wood samples at 3% produced inhibitions of 54.44% and 41.11%, respectively, against R. solani. Full article

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24 pages, 4636 KiB

Open AccessArticle

Mass Spectroscopic Analysis, MNDO Quantum Chemical Studies and Antifungal Activity of Essential and Recovered Oil Constituents of Lemon-Scented Gum against Three Common Molds

by Said I. Behiry, Ramadan A. Nasser, Mamoun S.M. Abd El-Kareem, Hayssam M. Ali and Mohamed Z.M. Salem

Processes 2020, 8(3), 275; https://doi.org/10.3390/pr8030275 - 27 Feb 2020

Cited by 25 | Viewed by 3691

Abstract

The present study described the possibility of using wood-treated oil-fungicide of lemon-scented gum (Corymbia citriodora) from newly emerged leaves and unripened fruits against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum. Air-dried wood samples of Melia azedarach [...] Read more.

The present study described the possibility of using wood-treated oil-fungicide of lemon-scented gum (Corymbia citriodora) from newly emerged leaves and unripened fruits against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum. Air-dried wood samples of Melia azedarach were treated with the extracted oils from leaves and unripened fruits from C. citriodora. The main chemical constituents identified in the essential oil (EO) from leaves were citronellal (55.31%), citronellol (21.03%) and isopulegol (10.79%), while in unripened fruits were α-pinene (17.86%), eudesmol (13.9%), limonene (9.19%), γ-terpinen (8.21%), and guaiol (7.88%). For recovered oils (ROs), the major components from leaves were D-limonene (70.23%), γ-terpinene (13.58%), β-pinene (2.40%) and isopregol (2.23%), while, 4-terpineol (21.35%), cis-β-terpineol, (19.33%), D-limonene (14.75%), and γ-terpinene (7.42%) represented the main components in fruits. EOs from leaves and fruits at the amounts of 100, 50 and 25 µL showed the highest inhibition percentage (IP) of 100% against F. culmorum and P. chrysogenum compared to control treatment, while at the amounts of 100, and 50 µL showed 100% IP of R. solani. Wood treated with ROs from leaves and fruits showed IPs of 96.66% and 93.33%, respectively, against the growth of R. solani. The mass spectra of the main components of C. citriodora leaves and fruits’ EOs have been recorded in electron ionization mode at 70 eV and fragmentation has been reported and discussed. On the other hand, different quantum parameters such as the heat of formation, ionization energy total energy, binding energy, electronic energy and dipole moment using the modified neglect of diatomic overlap (MNDO) semi-empirical method have been calculated. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 2750 KiB

Open AccessArticle

Process Parameters Optimization of Gallic Acid Removal from Water by MIEX Resin Based on Response Surface Methodology

by Qiang Zhou, Lei Ding, Yunhua Zhu, Meiying Zhong and Chuchu Yang

Processes 2020, 8(3), 273; https://doi.org/10.3390/pr8030273 - 27 Feb 2020

Cited by 11 | Viewed by 3712

Abstract

In this work, the response surface methodology was used to optimize the process parameters of gallic acid adsorption on magnetic ion exchange (MIEX) resin. Based on Box-Behnken Design, a quadratic polynomial model equation including solution pH, gallic acid concentration, MIEX resin dosage and [...] Read more.

In this work, the response surface methodology was used to optimize the process parameters of gallic acid adsorption on magnetic ion exchange (MIEX) resin. Based on Box-Behnken Design, a quadratic polynomial model equation including solution pH, gallic acid concentration, MIEX resin dosage and adsorption time was established. The reliability of the established regression equation was tested by variance analysis. Based on the regression equation, the technical parameters for gallic acid adsorption on MIEX resin were optimized and the effects of interaction between variables on the removal of gallic acid were analyzed. The results showed that the established regression equation was reliable and could effectively predict the removal of gallic acid. The optimal technical parameters were determined to be a pH of 9.17, a gallic acid concentration of 8.07 mg/L, a resin dosage of 0.98 mL/L and an adsorption time of 46.43 min. The removal efficiency of gallic acid was 97.93% under the optimal parameters. The interaction between pH and adsorption time had the most significant effect on the removal of gallic acid. The results of this study demonstrated that MIEX resin can remove gallic acid efficiently and relatively quickly under the condition of optimal technical parameters. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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18 pages, 5981 KiB

Open AccessArticle

Extraction of Cobalt and Iron from Refractory Co-Bearing Sulfur Concentrate

by Junhui Xiao and Yushu Zhang

Processes 2020, 8(2), 200; https://doi.org/10.3390/pr8020200 - 06 Feb 2020

Cited by 15 | Viewed by 8396

Abstract

In this study, oxidizing roasting, segregation roasting, and magnetic separation are used to extract cobalt and iron from refractory Co-bearing sulfur concentrate. The Co-bearing sulfur concentrate containing 0.68% Co, 33.26% Fe, and 36.58% S was obtained from V-Ti magnetite in the Panxi area [...] Read more.

In this study, oxidizing roasting, segregation roasting, and magnetic separation are used to extract cobalt and iron from refractory Co-bearing sulfur concentrate. The Co-bearing sulfur concentrate containing 0.68% Co, 33.26% Fe, and 36.58% S was obtained from V-Ti magnetite in the Panxi area of China by flotation. Cobalt pyrite and linneite were the Co-bearing minerals, and the gangue minerals were mica, chlorite, feldspar, and calcite in Co-bearing sulfur concentrate. The results show that cobalt is transformed from Co-pyrite and linneite to a Co₂FeO₄-dominated new cobalt mineral phase, and iron is transformed from pyrite to Fe₂O₃ and an Fe₃O₄-dominated new iron mineral phase after oxidizing roasting. Cobalt changed from CoFe₂O₄ to a new cobalt mineral phase dominated by [Co] Fe solid solution, and iron changed from Fe₂O₃ to a new iron mineral phase dominated by metal Fe and Fe₃O₄ after segregation roasting. Cobalt concentrate with a cobalt grade of 15.15%, iron content of 71.22%, and cobalt recovery of 90.81% as well as iron concentrate with iron grade of 60.06%, cobalt content of 0.11%, and iron recovery of 76.23% are obtained. The main minerals in the cobalt concentrate are Fe, [Co]Fe, Fe₃O₄, and SiO₂, and the main minerals in the iron concentrate are Fe₃O₄, FeO, Ca₂Si₂O₄, and Ca₂Al₂O₄. Full article

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13 pages, 3288 KiB

Open AccessArticle

The Potential Antibacterial and Antifungal Activities of Wood Treated with Withania somnifera Fruit Extract, and the Phenolic, Caffeine, and Flavonoid Composition of the Extract According to HPLC

by Mervat EL-Hefny, Mohamed Z. M. Salem, Said I. Behiry and Hayssam M. Ali

Processes 2020, 8(1), 113; https://doi.org/10.3390/pr8010113 - 16 Jan 2020

Cited by 36 | Viewed by 5512

Abstract

In the present study, Melia azedarach wood blocks treated with different acetone extract concentrations from Withania somnifera fruits are assessed for their antibacterial and anti-fungal activities. Wood blocks of M. azedarach treated with W. somnifera fruit extract at concentrations of 0, 1, 2, [...] Read more.

In the present study, Melia azedarach wood blocks treated with different acetone extract concentrations from Withania somnifera fruits are assessed for their antibacterial and anti-fungal activities. Wood blocks of M. azedarach treated with W. somnifera fruit extract at concentrations of 0, 1, 2, and 3% are evaluated for in vitro antimicrobial activity against five genbank accessioned bacterial strains—Agrobacterium tumefaciens, Dickeya solani, Erwinia amylovora, Pseudomonas cichorii, and Serratia pylumthica—and two fungi, namely, Fusarium culmorum and Rhizoctonia solani. Through HPLC analysis we find that the most abundant quantified phenolic and flavonoid compounds of acetone extract (mg/100 g) are salicylic acid (9.49), vanillic acid (4.78), rutin (4702.58), and myricetin (1386.62). Wood treated with the extract at 2% and 3% show no growth of A. tumefaciens, E. amylovora, and P. cichorii. Use of the extract at 3% causes inhibition of fungal mycelia of F. culmorum and R. solani by 84.07% and 67.03%, respectively. In conclusion, potent antifungal and antibacterial activity against plant pathogens is found when an acetone extract of W. somnifera fruits is applied to wood samples. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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19 pages, 6935 KiB

Open AccessArticle

The Biofungicide Activity of Some Plant Essential Oils for the Cleaner Production of Model Linen Fibers Similar to Those Used in Ancient Egyptian Mummification

by Maisa M. A. Mansour, Mervat EL-Hefny, Mohamed Z. M. Salem and Hayssam M. Ali

Processes 2020, 8(1), 79; https://doi.org/10.3390/pr8010079 - 07 Jan 2020

Cited by 25 | Viewed by 3557

Abstract

In this work, the essential oils (EOs) from Eriocephalus africanus leaf, Vitex agnus-castus leaf and fruit, Cymbopogon citratus leaf, and Rosmarinus officinalis leaf were used as antifungal agents against isolated Aspergillus flavus, Cladosporium cladosporioides, and Penicillium chrysogenum from an ancient Egyptian [...] Read more.

In this work, the essential oils (EOs) from Eriocephalus africanus leaf, Vitex agnus-castus leaf and fruit, Cymbopogon citratus leaf, and Rosmarinus officinalis leaf were used as antifungal agents against isolated Aspergillus flavus, Cladosporium cladosporioides, and Penicillium chrysogenum from an ancient Egyptian child’s mummy. The isolated fungi were used to colonize the samples of linen fibers. The best oil was used as a novel natural product for the cleaner production of model linen fibers similar to those used in ancient Egyptian mummification. Standard and original linen fibers were compared with the infected Linen samples using Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses. The FTIR revealed the changes in the molecular structure of the cellulose, hemicellulose, and lignin of the infected linen fibers. The cellulose crystallinity indices decreased to 64.61%, 52.69%, and 54.63% in the linen inoculated with A. flavus, C. cladosporioides, and P. chrysogenum compared to the control sample (72.08%), thereby affecting the chemical properties of the cellulose. The mycelia inhibition percentages of the three fungi reached 100% after the leaf EO from V. agnus-castus was applied, followed by C. citratus. The V. agnus-castus leaf EO applied at contraptions of 250, 500, 50, 1000, and 2000 µL/mL showed 100% inhibition for A. flavus and P. chrysogenum and reached 100% against C. cladosporioides at concentrations of 500, 750, 1000, and 2000 µL/mL. C. citratus leaf essential oil applied at concentrations of 500, 750, 1000, and 2000 µL/mL showed 100% inhibition to the growth of A. flavus and C. cladosporioides and reached 100% inhibition against the growth of P. chrysogenum at concentrations of 750, 1000 and 2000 µL/mL. This inhibition could be related to the main compounds of caryophyllene (23.13%), eucalyptol (20.59%), sabinene (β-thujene) (12.2%), γ-elemene (9%), and β-farnesene (6.14%) identified in V. agnus-castus leaf EO or due to the main compounds of β-citral (43.63%) and geranial (41.51%), as identified in the leaf EO of C. citratus by GC/MS. The morphological changes in the hyphae of the fungi were observed via SEM examination, where V. agnus-castus leaf EO, the best active oil, showed potent inhibition to fungi grown on the model linen fiber. In this way, the morphology and the structure of the hyphae were effectively changed. Our findings prove that the designed model linen fiber treated with V. agnus-castus leaf EO is able to preserve wrapping fibres and represents a novel natural alternative for effective fungicidal treatment. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 2677 KiB

Open AccessArticle

Elevated Bioactivity of Ruta graveolens against Cancer Cells and Microbes Using Seaweeds

by Eman A. Mahmoud, Hosam O. Elansary, Diaa O. El-Ansary and Fahed A. Al-Mana

Processes 2020, 8(1), 75; https://doi.org/10.3390/pr8010075 - 06 Jan 2020

Cited by 9 | Viewed by 3762

Abstract

Human cancer and pathogenic microbes cause a significant number of deaths every year. Modulating current sources of natural products that control such diseases becomes essential. Natural algae, such as Ascophyllum nodosum and Ecklonia maxima, can modulate the metabolic processes as well the bioactivities [...] Read more.

Human cancer and pathogenic microbes cause a significant number of deaths every year. Modulating current sources of natural products that control such diseases becomes essential. Natural algae, such as Ascophyllum nodosum and Ecklonia maxima, can modulate the metabolic processes as well the bioactivities of Ruta graveolens L. The R. graveolens plants were subjected to nine soil drenches of A. nodosum (7 mL L⁻¹), E. maxima (7 mL L⁻¹), or both extracts. Morphological performance, gas exchange parameters, and essential oils (EOs) composition (GC-MS) were studied and the bioactivity was assessed against several cancer cells and pathogenic bacteria or fungi. Treatment with A. nodosum + E. maxima seaweed extracts (SWE) led to the highest morphological performance and gas exchange parameters. The highest antiproliferative, apoptotic, and caspase-3/7 activities of EO were against HeLa in SWE mixture treated plants. The best EO antimicrobial activities were obtained against Staphylococcus aureus and Penicillium ochrochloron. SWE mixtures treated plants showed the best bioactivities against microbes and cancer cells. The highest abundance of 2-undecanone (62%) and 2-nonanone (18%) was found in plants treated with SWE mixtures and caused the best anticancer and antimicrobial effects. Seaweed mixtures act as natural elicitors of pharmaceutical industries and favored 2-undecanone and 2-nonanone in R. graveolens. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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19 pages, 3012 KiB

Open AccessArticle

Assessment of the Use of Natural Extracted Dyes and Pancreatin Enzyme for Dyeing of Four Natural Textiles: HPLC Analysis of Phytochemicals

by Mohamed Z. M. Salem, Ibrahim H. M. Ibrahim, Hayssam M. Ali and Hany M. Helmy

Processes 2020, 8(1), 59; https://doi.org/10.3390/pr8010059 - 02 Jan 2020

Cited by 29 | Viewed by 8559

Abstract

In the present study, four natural textiles (cotton, linen, wool, and silk) were dyed with 14 naturally extracted dyes, and pancreatin enzyme was used in the dyeing process. The effects of pancreatin enzyme and its buffer on naturally dyed textile samples were evaluated. [...] Read more.

In the present study, four natural textiles (cotton, linen, wool, and silk) were dyed with 14 naturally extracted dyes, and pancreatin enzyme was used in the dyeing process. The effects of pancreatin enzyme and its buffer on naturally dyed textile samples were evaluated. Two concentrations of pancreatin enzyme and buffer were used as pretreatments for dyed textiles. Proteinic fabrics showed the highest relative color strength (RCS) values of 137.23% and 132.2% when the pancreatin enzyme was applied on wool and silk dyed with pomegranate skin and bloodroot at concentrations A and B, respectively. Linen fiber dyed with catechu tree showed the highest total color difference (TCD) values with buffer (6.83) and pancreatin enzyme A (5.7) and B (6.3). This shows that there were no side effects of the pancreatin enzyme on the studied dyed textiles. By high-performance liquid chromatography (HPLC) analysis, the root extract from madder showed the presence of salicylic acid (1758.91 mg/kg extract), quercetin (844.23 mg/kg extract), ellagic acid (784.86 mg/kg extract) and benzoic acid (582.68 mg/kg extract) as main compounds. In cochineal extract the main compounds were rutin (37.732 mg/kg extract), kampherol (1915.98 mg/kg extract), myricetin (809.97 mg/kg extract), quercetin (496.76 mg/kg extract) and salicylic acid (193.87 mg/kg extract). Full article

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24 pages, 2600 KiB

Open AccessArticle

Toxicological Activity of Some Plant Essential Oils Against Tribolium castaneum and Culex pipiens Larvae

by Ahmed M. El-Sabrout, Mohamed Z. M. Salem, May Bin-Jumah and Ahmed A. Allam

Processes 2019, 7(12), 933; https://doi.org/10.3390/pr7120933 - 07 Dec 2019

Cited by 21 | Viewed by 3683

Abstract

In the present work, essential oils (EOs) from Schinus terebinthifolius (ripe and unripe fruits and leaves), Origanum majorana (air-dried aerial parts), and Psidium guajava (leaves) were assayed for their insecticidal activity against red flour beetle (Tribolium castaneum) and Culex mosquito larvae [...] Read more.

In the present work, essential oils (EOs) from Schinus terebinthifolius (ripe and unripe fruits and leaves), Origanum majorana (air-dried aerial parts), and Psidium guajava (leaves) were assayed for their insecticidal activity against red flour beetle (Tribolium castaneum) and Culex mosquito larvae (Culex pipiens). Several components were identified in the EOs using Gas chromatography–mass spectrometry (GC/MS), of which Δ-3-carene (25.9%), γ-terpinene (19.4), and γ-elemene (7.1%) were the major ones in S. terebinthifolius ripe fruits, α-pinene (48.9%), germacrene D (12.9%), and α-thujene (7.7%) in S. terebinthifolius unripe fruits, γ-elemene (11.7%), spathulenol (10.1%), β-elemene (9.2%), and p-cymene (9.1%) in S. terebinthifolius leaves, α-pinene (25.5%), (E)-caryophyllene (15.7%), (E)-nerolidol (16.7%), and cedran-8-ol (8.8%) in P. guajava leaves, and terpinen-4-ol (21.7%), γ-terpinene (16.5%), and sabinene (10.1%) in O. majorana air-dried aerial parts. The lethal concentration (LC₅₀) was calculated for tested EOs at different time periods (after 6, 12, 24, 48, and 72 h). After 6 h of treatment, the LC₅₀ was 33.3 and 6.8 µg/L air for S. terebinthifolius ripe and unripe fruits, respectively, and >40 µg/L air for EOs of S. terebinthifolius leaves, O. majoranaair-dried aerial parts, and P. guajava leaves. After 24 h of treatment, the LC₅₀ was 4.2, <2, 5, >40, and 6.1 µg/L air for EOs of S. terebinthifolius ripe fruits and leaves, O. majorana leaves, and P. guajava leaves, respectively. On the other hand, the LC₅₀ values decreased when the exposed period was increased to 72 h, and were <2 µg/L air for EOs of S. terebinthifolius ripe fruits, unripe fruits, and leaves along with P. guajava leaves, respectively, and 37.912 for EO of O. majorana leaves. The LC₅₀ value after 24 h of exposure of S. terebinthifolius unripe fruit EO was under 2 µg/L air, which means that the EO of S. terebinthifolius ripe fruit had a strong effect on adult T. castaneum adults compared to other tested EOs using the fumigation method. The present data confirm that the EOs of O. majorana leaves and S. terebinthifolius unripe fruits and leaves were more effective as larvicide than the EOs of S. terebinthifolius ripe fruits and P. guajava leaves on C. pipiens at a higher concentration (100 mg/L) when applied by the dipping method. EOs from S. terebinthifolius unripe or ripe fruits and leaves and P. guajava leaves were more effective as adulticide than EO of O. majorana leaves against T. castaneum when applied by the fumigant method. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 276 KiB

Open AccessArticle

Assessment of the Toxicity of Natural Oils from Mentha piperita, Pinus roxburghii, and Rosa spp. Against Three Stored Product Insects

by Marwa I. Mackled, Mervat EL-Hefny, May Bin-Jumah, Trandil F. Wahba and Ahmed A. Allam

Processes 2019, 7(11), 861; https://doi.org/10.3390/pr7110861 - 18 Nov 2019

Cited by 21 | Viewed by 3787

Abstract

Three natural oils extracted from Mentha piperita, Pinus roxburghii, and Rosa spp. were assessed in order to determine their insecticidal activity against the adults of three stored product insects: the rice weevil (Sitophilus oryzae L.), the lesser grain borer ( [...] Read more.

Three natural oils extracted from Mentha piperita, Pinus roxburghii, and Rosa spp. were assessed in order to determine their insecticidal activity against the adults of three stored product insects: the rice weevil (Sitophilus oryzae L.), the lesser grain borer (Rhyzopertha dominica, Fabricius), and the red flour beetle (Tribolium castaneum, Herbst.). By Gas chromatography–mass spectrometry (GC/MS) analysis, the main compounds in the n-hexane oil from Rosa spp. were determined to be methyl eugenol (52.17%), phenylethyl alcohol (29.92%), diphenyl ether (7.75%), and geraniol (5.72%); in the essential oil from M. piperita, they were menthone (20.18%), 1,8-cineole (15.48%), menthyl acetate (13.13%), caryophyllene (4.82%), β-pinene (4.37%), and D-limonene (2.81%); and from the foliage of P. roxburghii, they were longifolene (19.52%), caryophyllene (9.45%), Δ-3-carene (7.01%), α-terpineol (6.75%), and γ-elemene (3.88%). S. oryzae and R. dominica were reared using sterilized wheat grains, and T. castaneum was reared on wheat flour mixed with yeast (10:1, w/w), all under laboratory conditions (27 ± 1 °C and 65% ± 5% Relative humidity (R.H). Two toxicity bioassays were used, as well as contact using thin film residues and fumigation bioassays. The results indicated that M. piperita caused a high toxicity for S. oryzae compared to other insects. High significant variations were observed between the tested M. piperita doses against the stored insects, and this natural material could be used to control insects that infect the grains. Also, the data indicated that the Rosa spp. oil had a low-toxicity effect against these insects compared to other oils. We recommend using natural oils against the stored weevils and petals, rather than the chemical agent, so as to serve human health. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

19 pages, 2673 KiB

Open AccessArticle

Effects of Processing Conditions on the Simultaneous Extraction and Distribution of Oil and Protein from Almond Flour

by Neiva M. de Almeida, Fernanda F. G. Dias, Maria I. Rodrigues and Juliana M. L. N. de Moura Bell

Processes 2019, 7(11), 844; https://doi.org/10.3390/pr7110844 - 11 Nov 2019

Cited by 15 | Viewed by 4877

Abstract

The enzyme-assisted aqueous extraction process (EAEP) is an environmentally friendly strategy that simultaneously extracts oil and protein from several food matrices. The aim of this study was to investigate the effects of pH (6.5–9.5), temperature (45–55 °C), solids-to-liquid ratio (SLR) (1:12–1:8), and amount [...] Read more.

The enzyme-assisted aqueous extraction process (EAEP) is an environmentally friendly strategy that simultaneously extracts oil and protein from several food matrices. The aim of this study was to investigate the effects of pH (6.5–9.5), temperature (45–55 °C), solids-to-liquid ratio (SLR) (1:12–1:8), and amount of enzyme (0.5–1.0%) on the extraction and separation of oil and protein from almond flour using a fractional factorial design. Oil and protein extraction yields from 61 to 75% and 64 to 79% were achieved, respectively. Experimental conditions resulting in higher extractability were subsequently replicated for validation of the observed effects. Oil and protein extraction yields of 75 and 72% were achieved under optimized extraction conditions (pH 9.0, 50 °C, 1:10 SLR, 0.5% (w/w) of enzyme, 60 min). Although the use of enzyme during the extraction did not lead to significant increase in extraction yields, it did impact the extracted protein functionality. The use of enzyme and alkaline pH (9.0) during the extraction resulted in the production of more soluble peptides at low pH (5.0), highlighting possible uses of the EAEP skim protein in food applications involving acidic pH. The implications of the use of enzyme during the extraction regarding the de-emulsification of the EAEP cream warrant further investigation. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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12 pages, 1547 KiB

Open AccessArticle

Essential and Recovery Oils from Matricaria chamomilla Flowers as Environmentally Friendly Fungicides Against Four Fungi Isolated from Cultural Heritage Objects

by Mervat EL-Hefny, Wael A.A. Abo Elgat, Asma A. Al-Huqail and Hayssam M. Ali

Processes 2019, 7(11), 809; https://doi.org/10.3390/pr7110809 - 04 Nov 2019

Cited by 24 | Viewed by 4273

Abstract

Recovery oils, obtained from the hydro-distillation of the fresh flowers of Matricaria chamomilla, as well as essential oils, were studied for their environmental purposes in cultural heritage. These oils were assayed for their antifungal activity against the growth of four molds isolated [...] Read more.

Recovery oils, obtained from the hydro-distillation of the fresh flowers of Matricaria chamomilla, as well as essential oils, were studied for their environmental purposes in cultural heritage. These oils were assayed for their antifungal activity against the growth of four molds isolated from archaeological manuscripts (Aspergillus niger), museum gypsum board Antique (A. flavus), museum archaeological tissue (A. terreus), and museum organic materials (Fusarium culmorum) of cultural heritage objects. Oils were applied to inhibit the growth of fungi at amounts of 25, 50, 75 and, 100 µL/mL, and compared with negative controls (0 µL/mL) or positive controls (Sertaconazol 3g/L). Using GC/MS analysis, the main chemical compounds identified in the essential oil were (Z)-β-farnesene (27%), D-limonene (15.25%), and α-bisabolol oxide A (14.9%), while the compounds identified in the recovery oil were α-bisabolol oxide A (18.6%), d-limonene (8.82%), and α-bisabolol oxide B (7.13%). A low amount of chamazulene was observed in both essential and recovery oils, with amounts of 0.73% and 3.50%, respectively. Recovery oil, at a concentration of 75 and 100 µL/mL, showed fungal mycelial inhibition (FMI) percentage for the growth of A. niger, with values of 78% and 85%, respectively. At a concentration of 100 µL/mL, both oils showed 100% FMI of A. terreus. Oils showed weak activity against the growth of A. flavus. Essential oils at 100 µL/mL had good activity against the growth of F. culmorum, with FMI of 86.6%. The results suggest the potential use of essential and recovery oils from M. chamomilla fresh flowers as environmentally friendly bio-fungicides. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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14 pages, 1822 KiB

Open AccessArticle

Optimization of Enzyme-Assisted Extraction of Flavonoids from Corn Husks

by Antonio Zuorro, Roberto Lavecchia, Ángel Darío González-Delgado, Janet Bibiana García-Martinez and Pasqua L’Abbate

Processes 2019, 7(11), 804; https://doi.org/10.3390/pr7110804 - 03 Nov 2019

Cited by 25 | Viewed by 6206

Abstract

Corn husks are an important byproduct of the corn processing industry. Although they are a rich source of bioactive compounds, especially flavonoids, corn husks are usually disposed of or used as animal feed. In this paper, we investigate their recovery by an enzyme-assisted [...] Read more.

Corn husks are an important byproduct of the corn processing industry. Although they are a rich source of bioactive compounds, especially flavonoids, corn husks are usually disposed of or used as animal feed. In this paper, we investigate their recovery by an enzyme-assisted extraction process consisting of a pretreatment of the plant material with cellulase followed by solvent extraction with aqueous ethanol. A four-factor, three-level Box–Behnken design combined with the response surface methodology was used to optimize the enzyme dosage (0.3–0.5 g/100 g), incubation time (1.5–2.5 h), liquid-to-solid ratio (30–40 mL g⁻¹) and ethanol concentration in the solvent (60–80% v/v). Under the optimal conditions, about 1.3 g of total flavonoids per 100 g of dry waste were recovered. A statistical analysis of the results was performed to provide a quantitative estimation of the influence of the four factors, alone or in combination, on the extraction yields. Overall, the results from this study indicate that corn husks are a valuable source of flavonoids and that they can be easily recovered by a sustainable and environmentally friendly extraction process. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 1799 KiB

Open AccessArticle

Oil Recovery from Palm Kernel Meal Using Subcritical Water Extraction in a Stirred Tank Reactor

by Johnnys Bustillo Maury, Andrés Aldana Rico, Cindy García Pinto, Ingrid Hernández Medina, Juan Urueta Urueta, Jerry W. King and Antonio Bula Silvera

Processes 2019, 7(11), 797; https://doi.org/10.3390/pr7110797 - 02 Nov 2019

Cited by 1 | Viewed by 2493

Abstract

Palm kernel meal (PKM) is one of the main byproducts of the oil palm industry. PKM can be obtained as the result of solvent or mechanical extraction of palm kernel oil; in both cases, meal has a remaining oil content that could be [...] Read more.

Palm kernel meal (PKM) is one of the main byproducts of the oil palm industry. PKM can be obtained as the result of solvent or mechanical extraction of palm kernel oil; in both cases, meal has a remaining oil content that could be recovered. In this work, PKM coming from a mechanical pressing extraction system with an initial oil content between 7 to 8% (wt.) was treated with subcritical water in a batch stirred reactor. To find the proper operational conditions, a three-step experimental process was performed. Extraction temperature, reaction time, particle size and alkaline catalyst usage were selected as process factors. After subcritical extraction, the system was cooled down and depressurized; then oil phase was separated by centrifugation. After extraction, meal was oven-dried at 80 °C. A maximum recovery of 0.034 kg-oil/kg-meal was obtained at 423 K, 720 s and particles smaller than 0.001 m. The experimental procedure showed consistent extraction yields of 40% without modifying the quality of the obtained oil. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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12 pages, 601 KiB

Open AccessCommunication

Antifungal Activity of Euclea divinorum Root and Study of its Ethnobotany and Phytopharmacology

by Mohamed Al-Fatimi

Processes 2019, 7(10), 680; https://doi.org/10.3390/pr7100680 - 01 Oct 2019

Cited by 10 | Viewed by 3977

Abstract

The ethnobotanical survey of Euclea divinorum Hiern (Ebenaceae) was conducted on Soqotra Island, Yemen. The root bark is used to treat mouth, dental, dermal and blood diseases in the traditional medicine of the island. The study is the first report about the effect [...] Read more.

The ethnobotanical survey of Euclea divinorum Hiern (Ebenaceae) was conducted on Soqotra Island, Yemen. The root bark is used to treat mouth, dental, dermal and blood diseases in the traditional medicine of the island. The study is the first report about the effect of the plant root barks against six human pathogenic fungi. The non-polar dichloromethane extract of Euclea divinorum root bark showed stronger antifungal activities compared to polar direct and sequential methanolic extracts. These extracts showed significant broad antifungal activity against Absidia corymbifera, Aspergillus fumigatus, Candida krusei, Microsporum gypseum, Mucor sp. and Trichophyton mentagrophytes compared to the standard antibiotic drug nystatin. Thin-layer chromatography (TLC) revealed the presence of the naphthoquinones in the extracts. The results showed an extraction process to separate most antifungal naphthoquinones from the root bark by using non-polar solvent dichloromethane, while flavonoids remained in the polar methanolic extracts; therefore, the polar sequential and direct methanolic extracts recorded higher antioxidant activity than the non-polar extracts with less toxicity. The biological and chemical results identified the presence of antifungal and antioxidant constituents in the root bark and confirm its traditional use in Soqotra Island as crude powder to treat dental and dermal diseases and to clean teeth. Moreover, our results are compared with literature review on ethnobotany and phytopharmacology of E. divinorum to present a medicinal monograph about the plant. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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20 pages, 3303 KiB

Open AccessArticle

Recovering Cobalt and Sulfur in Low Grade Cobalt-Bearing V–Ti Magnetite Tailings Using Flotation Process

by Junhui Xiao and Yushu Zhang

Processes 2019, 7(8), 536; https://doi.org/10.3390/pr7080536 - 14 Aug 2019

Cited by 13 | Viewed by 6141

Abstract

There is 0.032% cobalt and 0.56% sulfur in the cobalt-bearing V–Ti tailings in the Panxi Region, with the metal sulfide minerals mainly including FeS₂, Fe_1−xS, Co₃S₄, and (Fe,Co)S₂, and the gangue minerals mainly [...] Read more.

There is 0.032% cobalt and 0.56% sulfur in the cobalt-bearing V–Ti tailings in the Panxi Region, with the metal sulfide minerals mainly including FeS₂, Fe_1−xS, Co₃S₄, and (Fe,Co)S₂, and the gangue minerals mainly including aluminosilicate minerals. The flotation process was used to recover cobalt and sulfur in the cobalt-bearing V–Ti tailings. The results showed that an optimized cobalt–sulfur concentrate with a cobalt grade of 2.08%, sulfur content of 36.12%, sulfur recovery of 85.79%, and cobalt recovery and 84.77% were obtained by flotation process of one roughing, three sweeping, and three cleaning under roughing conditions, which employed pulp pH of 8, grinding fineness of <0.074 mm occupying 80%, flotation concentration of 30%, and dosages of butyl xanthate, copper sulfate, and pine oil of 100 g/t, 30 g/t, and 20 g/t, respectively. Optimized one sweeping, two sweeping, and three sweeping conditions used a pulp pH of 9, and dosages of butyl xanthate, copper sulfate, and pine oil of 50 g/t, 15 g/t, 10 g/t; 25 g/t, 7.5 g/t, 5 g/t; 20 g/t, 5 g/t, 5 g/t, respectively. Optimized one cleaning, two cleaning, and three cleaning condition dosages of sodium silicate of 200 g/t, 100 g/t, 50 g/t, respectively. Study of analysis and characterization of cobalt–sulfur concentrate by X-ray diffraction (XRD), automatic mineral analyzer (MLA), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) showed that the main minerals in cobalt–sulfur concentrate are FeS_2, Co₃S₄ and (Fe,Co)S₂, of which FeS₂ and (Fe,Co)S₂ accounted for 65.64% and Co₃S₄ for 22.64%. Gangue minerals accounted for 11.72%. The element Co in (Fe,Co)S₂ is closely related to pyrite in the form of isomorphism, and the flotability difference between cobalt and pyrite is very small, which makes it difficult to separate cobalt and sulfur. Cobalt–sulfur concentrate can be used as raw material for further separation of cobalt and sulfur in smelting by pyrometallurgical or hydrometallurgical methods. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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14 pages, 4544 KiB

Open AccessArticle

Green Synthesis of Potent Antimicrobial Silver Nanoparticles Using Different Plant Extracts and Their Mixtures

by May Reda, Akram Ashames, Zehra Edis, Samir Bloukh, Richie Bhandare and Hamed Abu Sara

Processes 2019, 7(8), 510; https://doi.org/10.3390/pr7080510 - 04 Aug 2019

Cited by 49 | Viewed by 8301

Abstract

Nano-sized metals have been introduced as a promising solution for microbial resistance to antimicrobial agents. Silver nanoparticles (AgNPs) have been proven to possess good antimicrobial activity. Green synthesis of AgNPs has been reported as safe, low cost and ecofriendly. This methodology uses extracts [...] Read more.

Nano-sized metals have been introduced as a promising solution for microbial resistance to antimicrobial agents. Silver nanoparticles (AgNPs) have been proven to possess good antimicrobial activity. Green synthesis of AgNPs has been reported as safe, low cost and ecofriendly. This methodology uses extracts originating from different plants to reduce silver ions from AgNO₃ into nano-sized particles. In this study, extracts of several plants including ginger, garlic, capsicum and their mixtures were successfully used to produce AgNPs. Numerous spectroscopic, light scattering and microscopic techniques were employed to characterize the synthesized AgNPs. Agar well diffusion assay was performed to investigate the antimicrobial activity of AgNPs. The biosynthesized AgNPs have spherical shape with a size range of 20–70 nm. Garlic extract, pure or in mixture with ginger extract, generated AgNPs of the smallest size. The presence of the plant-origin capping agents surrounding AgNPs was proven by Fourier-transform infrared spectroscopy. The AgNPs, at a concentration of 50 µg/mL, demonstrated potent antimicrobial activity against Staphyloccocus aureus, Escherichia coli and Candida albicans as indicated by the zones of inhibitions. Our results revealed that AgNPs having potent antimicrobial activity could be prepared using different pure plant extracts and their mixtures. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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18 pages, 3641 KiB

Open AccessArticle

Extraction Process of Polyphenols from Soybean (Glycine max L.) Sprouts: Optimization and Evaluation of Antioxidant Activity

by Xuan Tien Le, Vo Luu Lan Vi, Tran Quoc Toan, Long Giang Bach, Tran Thanh Truc and Pham Thi Hai Ha

Processes 2019, 7(8), 489; https://doi.org/10.3390/pr7080489 - 01 Aug 2019

Cited by 19 | Viewed by 5586

Abstract

This research aimed to optimize the total polyphenol content (TPC) extracted from soybean sprout powder under different experimental parameters, including ethanol concentration (60–100% v/v), extraction temperature (40–80 °C), extraction time (15–150 min), material:solvent ratio (1:4–1:10 g/mL), the number extraction cycles (1, 2 [...] Read more.

This research aimed to optimize the total polyphenol content (TPC) extracted from soybean sprout powder under different experimental parameters, including ethanol concentration (60–100% v/v), extraction temperature (40–80 °C), extraction time (15–150 min), material:solvent ratio (1:4–1:10 g/mL), the number extraction cycles (1, 2 and 3 times), the age of sprout (0–7 days), and the used part of the sprout (cotyledon, hypocotyl, or radicle). The obtained results were used in response surface methodology, in combination with a central composite design, to model the total polyphenol content (TPC) with respect to three variables, including ethanol concentration, extraction temperature, and material:solvent ratio. The experimental conditions for optimal recovery of TPC consisted of ethanol concentration of 88% (v/v), extraction temperature of 59 °C, material:solvent ratio of 1:6.5 g/mL, extraction time of 60 min, and 2 cycles of maceration. In addition, for maximal TPC, the sprout should undergo the germination of 5 days and the radicle fraction should be used. Based on the suggested optimum conditions, the obtained and verified TPC was 19.801 mg genistein (GE)/g dry weight (d.w.). The obtained dried extract also exhibited low antioxidant activity. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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21 pages, 7011 KiB

Open AccessArticle

Ultrasound-Assisted Extraction of Pectin from Malus domestica ‘Fălticeni’ Apple Pomace

by Florina Dranca and Mircea Oroian

Processes 2019, 7(8), 488; https://doi.org/10.3390/pr7080488 - 01 Aug 2019

Cited by 43 | Viewed by 5905

Abstract

The use of an ultrasonic treatment for the extraction of pectin from Malus domestica ‘Fălticeni’ apple pomace, its effects on extraction yield and galacturonic acid content, and degree of esterification of the extracted pectin were investigated. The optimization of the extraction process showed [...] Read more.

The use of an ultrasonic treatment for the extraction of pectin from Malus domestica ‘Fălticeni’ apple pomace, its effects on extraction yield and galacturonic acid content, and degree of esterification of the extracted pectin were investigated. The optimization of the extraction process showed that the highest yield of 9.183% pectin, with a 98.127 g/100 g galacturonic acid content and 83.202% degree of esterification, was obtained at 100% amplitude, pH of 1.8, SLR of 1:10 g/mL, and 30 min. The pectin obtained in optimal extraction conditions was compared to commercial citrus and apple pectin in terms of chemical composition (determined by FT-IR), thermal behaviour (analyzed by differential scanning calorimetry), rheological properties, and morphological structure (analyzed by scanning electron microscopy). By comparison to commercial citrus and apple pectin samples, the FT-IR analysis of pectin extracted by ultrasound treatment confirmed the high degree of esterification and showed similarity to that of apple pectin (88.526%). It was found that the thermal behaviour of the pectin obtained by ultrasound-assisted extraction was influenced by the narrower distribution of molecular weights and the orderly molecular arrangement, while the rheological properties (high viscosity, G0, and G1) of this sample were influenced by the morphological structure and the galacturonic acid content. The correlation coefficient showed a strong positive relationship between viscosity and galacturonic acid content (r = 0.992**). Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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13 pages, 1895 KiB

Open AccessArticle

Optimization of Microwave-Assisted Extraction of Total Phenolic and Total Flavonoid Contents from Fruits of Docynia indica (Wall.) Decne. Using Response Surface Methodology

by Xuan Duy Le, Manh Cuong Nguyen, Dinh Hoang Vu, Minh Quan Pham, Quoc Long Pham, Quang Tung Nguyen, Tuan Anh Nguyen, Van Thinh Pham, Long Giang Bach, Tuong Van Nguyen and Quoc Toan Tran

Processes 2019, 7(8), 485; https://doi.org/10.3390/pr7080485 - 01 Aug 2019

Cited by 25 | Viewed by 7671

Abstract

Docynia indica (D. indica) shows various useful biological activities, such as antioxidant, anti-inflammatory, antibacterial effects, and positive benefits for human health. Such biological activities relate to the main phytochemicals of D. indica including phenolic and flavonoid. However, isolation for phenolic and [...] Read more.

Docynia indica (D. indica) shows various useful biological activities, such as antioxidant, anti-inflammatory, antibacterial effects, and positive benefits for human health. Such biological activities relate to the main phytochemicals of D. indica including phenolic and flavonoid. However, isolation for phenolic and flavonoid by popular methods such as hot extraction, soxhlet extraction, and ultrasonic extraction have been relatively ineffective. Therefore, in this study, microwave-assisted extraction (MAE) was used for the extraction of total phenolic and total flavonoid from D. indica. The optimization experiments were conducted based on response surface methodology (RMS) according to a central composite design with four independent variables: extraction time (min), ethanol concentration (%, v/v), microwave power (W), and pH of the solvent. Three dependent variables were total phenolic content (TPC), total flavonoid content (TFC), and yield. The optimal conditions for the extraction of phenolic and flavonoid from D. indica were: extraction time of 50 min, ethanol concentration of 65%, microwave power of 440 W, and solvent pH of 5.4. These conditions corresponded to TPC, TFC, and yield values of 33.57 ± 0.12 (mg GAE/g), 25.01 ± 0.11 (mg QE/g) and 33.44 ± 0.14 (%), respectively. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 3990 KiB

Open AccessArticle

The Effect of Extraction Methods on Preliminary Structural Properties and Antioxidant Activities of Polysaccharides from Lactarius vividus

by Zhou Xu, Shiling Feng, Jipeng Qu, Ming Yuan, Ruiwu Yang, Lijun Zhou, Tao Chen and Chunbang Ding

Processes 2019, 7(8), 482; https://doi.org/10.3390/pr7080482 - 30 Jul 2019

Cited by 10 | Viewed by 3256

Abstract

Four polysaccharides (LVP-u, LVP-m, LVP-e, and LVP-h) were extracted from the fruiting bodies of Lactarius vividus by an ultrasonic-assisted extraction method, microwave-assisted extraction method, enzyme-assisted extraction method, and hot water extraction method, respectively. Then, the effect of extraction methods on yields, preliminary structural [...] Read more.

Four polysaccharides (LVP-u, LVP-m, LVP-e, and LVP-h) were extracted from the fruiting bodies of Lactarius vividus by an ultrasonic-assisted extraction method, microwave-assisted extraction method, enzyme-assisted extraction method, and hot water extraction method, respectively. Then, the effect of extraction methods on yields, preliminary structural properties, and antioxidant activities was systematically investigated using the weighing method, chemical composition analysis, high-performance gel permeation chromatography (HPGPC), high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), radical scavenging, and metal ion chelating assays. Results demonstrated that the four L. vividus polysaccharides (LVPs) were all combined with protein, and the yield of LVP-u was higher than others. Molecular weight distribution, monosaccharide and amino acid compositions, and microstructures among the four LVPs were significantly different. Moreover, the LVPs showed significant antioxidant activities in a dose-dependent manner, and LVP-e demonstrated better antioxidant activities in superoxide anion radical scavenging activity assays and metal ion chelating activity assays, while LVP-u showed higher activity in its hydroxyl radical scavenging ability. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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12 pages, 2295 KiB

Open AccessArticle

Sustainable Green Procedure for Extraction of Hesperidin from Selected Croatian Mandarin Peels

by Stela Jokić, Silvija Šafranko, Martina Jakovljević, Ana-Marija Cikoš, Nikolina Kajić, Filip Kolarević, Jurislav Babić and Maja Molnar

Processes 2019, 7(7), 469; https://doi.org/10.3390/pr7070469 - 20 Jul 2019

Cited by 23 | Viewed by 6457

Abstract

The peels of Citrus reticulata Blanco mandarin cultivars of different Croatian varieties (Zorica rana, Chahara, Okitsu, Kuno) were extracted using 15 different choline chloride-based deep eutectic solvents (DESs) at 50 °C for 30 min and with 20% water [...] Read more.

The peels of Citrus reticulata Blanco mandarin cultivars of different Croatian varieties (Zorica rana, Chahara, Okitsu, Kuno) were extracted using 15 different choline chloride-based deep eutectic solvents (DESs) at 50 °C for 30 min and with 20% water addition. The extracts were analyzed by high performance liquid chromatography with diode array detection (HPLC-DAD) to determine the most suitable DES for the extraction of hesperidin in the samples. The screening results indicated that choline chloride: acetamide (1:2) provided the most efficient hesperidin extraction (112.14 mg/g of plant), while choline chloride:citric acid (1:1) solvent showed the lowest hesperidin yield (1.44 mg/g of plant). The Box–Behnken design was employed to optimize extraction parameters for each variety of mandarin peel, including extraction time, temperature and water content on hesperidin extraction. The results indicated that hesperidin content in mandarin peels was completely variety-dependent. Being a novel and efficient green media for hesperidin extraction, deep eutectic solvents could also serve as promising solvent systems for the production of extracts rich in bioactive compounds. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 6311 KiB

Open AccessArticle

Optimization of Total Anthocyanin Content, Stability and Antioxidant Evaluation of the Anthocyanin Extract from Vietnamese Carissa Carandas L. Fruits

by Xuan Tien Le, Minh Thuan Huynh, Tri Nhut Pham, Van Thai Than, Tran Quoc Toan, Long Giang Bach and Nguyen Quang Trung

Processes 2019, 7(7), 468; https://doi.org/10.3390/pr7070468 - 20 Jul 2019

Cited by 65 | Viewed by 11417

Abstract

In this study, the extraction of anthocyanin colorant from karanda fruit (Carissa carandas L.) was carried out and optimized with multiple single factor assays. Selected conditions for yield maximization consisted of ripen fruits with black-purple color, material size of thin slices (1.0–1.5 [...] Read more.

In this study, the extraction of anthocyanin colorant from karanda fruit (Carissa carandas L.) was carried out and optimized with multiple single factor assays. Selected conditions for yield maximization consisted of ripen fruits with black-purple color, material size of thin slices (1.0–1.5 mm), solvent of EtOH 50%, material/ solvent ratio of 1:3, temperature of 50 °C, extraction time of 45 min, and two extraction cycles. The anthocyanin content in the extract was 277.2 mg/L, which is equivalent to 9.33 mg anthocyanin per gram of dry material. Aqueous solutions of the extract and dried extracts from Carissa carandas fruit were evaluated for stability at two temperature conditions, namely room temperature (30 ± 2 °C) and 45 °C. The temperature exerted great impact on color change, anthocyanin content and the degree of polymerization of anthocyanin. Aqueous solutions of extract with citric acid (3.0–5.0 g/L) were generally more color stable and less anthocyanin degradable than those without citric acid. In the DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging assay, The half maximal inhibitory concentration (IC₅₀) of the dried extract was 87.56 μg/mL, which was approximately 29 times higher than that of vitamin C. After 3-month storage at −18 °C, IC₅₀ of the dried extract was 173.67 μg/mL. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 2112 KiB

Open AccessArticle

Separation of Protein-Binding Anthraquinones from Semen Cassiae Using Two-Stage Foam Fractionation

by Linlin Ding, Yanyan Wang, Chuanjun Yue, Zeying Wu, Ye Sun, Min Wang and Rui Li

Processes 2019, 7(7), 463; https://doi.org/10.3390/pr7070463 - 19 Jul 2019

Cited by 3 | Viewed by 3025

Abstract

Anthraquinones are compounds of high medicinal value in many plants. Based on their good protein binding affinity, foam fractionation was attempted to separate them using proteins in the aqueous extract of Semen Cassiae as collectors. Firstly, the interaction between anthraquinones and Semen Cassiae [...] Read more.

Anthraquinones are compounds of high medicinal value in many plants. Based on their good protein binding affinity, foam fractionation was attempted to separate them using proteins in the aqueous extract of Semen Cassiae as collectors. Firstly, the interaction between anthraquinones and Semen Cassiae proteins has been analyzed by the Stem–Volmer equation with physcion as a standard. The results show that physcion had good interaction with the proteins via hydrophobic forces. More importantly, the proteins effectively assisted the foam fractionation of several anthraquinones including aurantio-obtusifolin, aloe-emodin, rhein, emodin, chrysophanol, and physcion. On this basis, a two-stage foam fractionation technology was developed for process intensification using a foam fractionation with vertical sieve trays (VSTs). VSTs, initial feed concentration of total anthraquinones, temperature, volumetric air flow rate and pore diameter of gas distributor had significant effects on enrichment ratio and recovery yield of anthraquinones. Under suitable conditions, the enrichment ratio of total anthraquinones reached 47.0 ± 4.5 with a concentration of 939 ± 94 mg/L in the foamate while their total recovery percentage reached more than 47.7%. In addition, foam fractionation also increased the purity and hydroxyl radical scavenging activity of total anthraquinones. The results had significant implications for the separation of anthraquinones from Semen Cassiae. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 1149 KiB

Open AccessArticle

Extraction Process, Identification of Fatty Acids, Tocopherols, Sterols and Phenolic Constituents, and Antioxidant Evaluation of Seed Oils from Five Fabaceae Species

by Lan Phuong Doan, Thi Thuy Nguyen, Minh Quan Pham, Quoc Toan Tran, Quoc Long Pham, Dinh Quang Tran, Van Thai Than and Long Giang Bach

Processes 2019, 7(7), 456; https://doi.org/10.3390/pr7070456 - 16 Jul 2019

Cited by 20 | Viewed by 5787

Abstract

The present study aimed to extract seed oils and characterize the chemical composition, including fatty acid profiles, tocopherols, sterols, and total phenolics of oils and extracts from five Fabaceae seeds: Glycine soja, Vigna angularis, Phaseolus lunatus, Phaseolus vulgarisand, and [...] Read more.

The present study aimed to extract seed oils and characterize the chemical composition, including fatty acid profiles, tocopherols, sterols, and total phenolics of oils and extracts from five Fabaceae seeds: Glycine soja, Vigna angularis, Phaseolus lunatus, Phaseolus vulgarisand, and Phaseolus coccineus. The composition and content of all substance layers in total lipids of the extracted seed oils from five Fabaceae species contain: polar lipid (PL), sterol (ST), diacylglycerol (DG), triacylglycerol (TG), free fatty acid (FFA), and hydrocarbon and wax (HC + W). Antioxidant activity determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was also estimated. Among these examined samples, Phaseolus vulgarisand and Phaseolus coccineus seed oils showed high content of α-linolenic acid (59.39% and 49.38%, respectively). Linoleic acid was abundantly found in Vigna angularis (49.01%). Ferunic and caffeic acid, γ-tocopherol, and β-sistosterol were the main ingredients present in the species studied. The V. angularis seed extract displayed significant antioxidant activity. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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9 pages, 378 KiB

Open AccessArticle

Isolation Process and Compound Identification of Agarwood Essential Oils from Aquilaria crassna Cultivated at Three Different Locations in Vietnam

by Dinh Thi Thu Thuy, Tran Thi Tuyen, Tran Thi Thu Thuy, Pham Thi Hong Minh, Quoc Toan Tran, Pham Quoc Long, Duy Chinh Nguyen, Long Giang Bach and Nguyen Quyet Chien

Processes 2019, 7(7), 432; https://doi.org/10.3390/pr7070432 - 09 Jul 2019

Cited by 29 | Viewed by 5817

Abstract

Agarwood and agarwood essential oils are commodities with great commercial value. In Vietnam, the agarwood industry has been growing, with more than 10,000 ha of forest land reserved for the cultivation of Aquilaria crassna, an agarwood-producing tree. The aim of this study [...] Read more.

Agarwood and agarwood essential oils are commodities with great commercial value. In Vietnam, the agarwood industry has been growing, with more than 10,000 ha of forest land reserved for the cultivation of Aquilaria crassna, an agarwood-producing tree. The aim of this study was to present a hydrodistillation process to recover agarwood essential oil and to compare chemical compositions of agarwood samples harvested from various locations in Vietnam. Three agarwood samples representing products from A. crassna trees cultivated in the provinces of Bac Giang and Khanh Hoa, and on the Phu Quoc island (Kien Giang province) of Vietnam were subjected to hydrodistillation, resulting in essential oil yields of 0.32%, 0.27%, and 0.25% (w/w), respectively. Using GC–MS analysis, a total of 44 volatile compounds were identified in the obtained oils. Most of the constituents were oxygenated sesquiterpenes and had been previously found in other agarwood oil samples. Notable compounds of other chemical classes were aromatics and fatty acids. The three oil samples showed a common volatile profile, which is characterized by the dominance of eremophilane, agarofurans, and eudesmane sesquiterpenes, while vetispirane and guaiane sesquiterpenes were found in smaller quantities. Desired compounds, such as neopetasane (7.47–8.29%), dihydrokaranone (2.63–3.59%), β-agarofuran (3.04–6.18%), and agarospirol (2.98–3.42%), were present in substantial quantities, suggesting that the essential oils could be commercialized as fragrant materials of high value. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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17 pages, 3523 KiB

Open AccessArticle

Increasing Iron and Reducing Phosphorus Grades of Magnetic-Roasted High-Phosphorus Oolitic Iron Ore by Low-Intensity Magnetic Separation–Reverse Flotation

by Junhui Xiao and Lingli Zhou

Processes 2019, 7(6), 388; https://doi.org/10.3390/pr7060388 - 21 Jun 2019

Cited by 16 | Viewed by 4562

Abstract

High-phosphorus oolitic iron ore, treated by suspended flash magnetic roasting, contained 42.73% iron (mainly present as magnetite) and 0.93% phosphorus (present as collophane). Low-intensity magnetic separation (LIMS) was combined with reverse flotation to increase the iron and reduce the phosphorus contents of the [...] Read more.

High-phosphorus oolitic iron ore, treated by suspended flash magnetic roasting, contained 42.73% iron (mainly present as magnetite) and 0.93% phosphorus (present as collophane). Low-intensity magnetic separation (LIMS) was combined with reverse flotation to increase the iron and reduce the phosphorus contents of the roasted product. The results showed that an optimized iron ore concentrate with an iron grade of 67.54%, phosphorus content of 0.11%, and iron recovery of 78.99% were obtained under LIMS conditions that employed a grind of 95% −0.038 mm and a magnetic field of 0.10 T. Optimized rougher reverse-flotation conditions used a pulp pH of 9 and dosages of toluenesulfonamide, starch, and pine alcohol oil of 800 g/t, 1000 g/t, and 40 g/t, respectively; optimized scavenging conditions used a pulp pH of 9 and dosages of toluenesulfonamide, starch, and pine alcohol oil of 400 g/t, 500 g/t, and 20 g/t, respectively. Study of the mechanism of phosphorus reduction showed that the toluenesulfonamide could be adsorbed on the surface of quartz after the action of starch, but adsorption was significantly weakened. The starch inhibitor negatively affected adsorption on quartz, but positively influenced adsorption of phosphorus minerals. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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13 pages, 1218 KiB

Open AccessArticle

Supercritical Fluid Extraction of Fat and Caffeine with Theobromine Retention in the Cocoa Shell

by Fanny Adabel González-Alejo, Juan Barajas-Fernández, María de los Ángeles Olán-Acosta, Laura Mercedes Lagunes-Gálvez and Pedro García-Alamilla

Processes 2019, 7(6), 385; https://doi.org/10.3390/pr7060385 - 21 Jun 2019

Cited by 11 | Viewed by 5400

Abstract

The cocoa shell is a residue of low commercial value, which represents an alternative for obtaining substances of added value for the food and pharmaceutical industry. Substances of interest in the shell include fat and methylxanthines (theobromine and caffeine). In order to obtain [...] Read more.

The cocoa shell is a residue of low commercial value, which represents an alternative for obtaining substances of added value for the food and pharmaceutical industry. Substances of interest in the shell include fat and methylxanthines (theobromine and caffeine). In order to obtain the extraction behavior with supercritical CO₂, a 2³ factorial design was proposed with six central points, taking dynamic extraction into consideration. The following factors were involved: pressure (2,000–6,000 psi), temperature (313–333 K), and time (30–90 min). The obtained yield was between 3.66% and 15.30%. Fat was the substance that was extracted most effectively (94.73%). Caffeine demonstrated variability in the residue, with at least six treatments that exceeded a removal rate of more than 90%, while it was practically impossible to extract theobromine. The difference with regard to the extraction of theobromine may be attributed to its low solubility. Characterization using FT–IR showed the modifications before and after the process, providing clear evidence of the changes corresponding to the fat at 2,924, 2,854 and 1,745 cm⁻¹. The results presented establish the basis for the extraction of substances such as fats and methylxanthines from a cocoa shell with the use of CO₂. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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18 pages, 2199 KiB

Open AccessArticle

Separation Emulsion via Non-Ionic Surfactant: An Optimization

by Murtada Mohammed Abdulredha, Siti Aslina Hussain and Luqman Chuah Abdullah

Processes 2019, 7(6), 382; https://doi.org/10.3390/pr7060382 - 20 Jun 2019

Cited by 26 | Viewed by 4376

Abstract

Achieving emulsion stability in the petroleum industry is a major challenge due to several problems encountered in the oil refining process, such as corrosion in equipment, high-pressure drops in pipelines, and catalyst poisoning in upstream facilities. Thus, several methods are applied for emulsion [...] Read more.

Achieving emulsion stability in the petroleum industry is a major challenge due to several problems encountered in the oil refining process, such as corrosion in equipment, high-pressure drops in pipelines, and catalyst poisoning in upstream facilities. Thus, several methods are applied for emulsion treatment and chemical treatment using surface-active agents, a fundamental method in the petroleum industry. The present work investigated the performance of a non-ionic surfactant in separating water in a crude oil emulsion via the bottle test technique. Then, a Fractional Factorial Design (2^K−1) was used to characterise the effect of significant variables. In particular, a Pareto chart was employed and factors such as demulsifier dosage, toluene concentration, pressure, sitting time, and temperature were investigated. Accordingly, the parameters applied were further analysed using a Central Composite Design (CCD) based on the Response Surface Method (RSM). The experimental results based on analysis of Variance (ANOVA) show that demulsifier dosage, temperature, and sedimentation times were the main variables affecting the dehydration process, with the highest F-values being 564.74, 94.53 and 78.65 respectively. The increase in the surfactant dosage before critical concentration, temperature and sitting time leads to boosting dehydration efficiency. In addition, a mathematical model was established for the variables, with a coefficient of determination value of 0.9688. Finally, numerical optimisation was performed on the variables and the results show that the optimal values are 1000 ppm, 15.5 mL, −400 mmHg, 120 min, and 90 °C, for demulsifier dosage, toluene concentration, pressure, sitting time, and temperature, respectively. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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13 pages, 4282 KiB

Open AccessArticle

A Novel Technology for Separating Copper, Lead and Zinc in Flotation Concentrate by Oxidizing Roasting and Leaching

by Qian Zhang, Qicheng Feng, Shuming Wen, Chuanfa Cui and Junbo Liu

Processes 2019, 7(6), 376; https://doi.org/10.3390/pr7060376 - 18 Jun 2019

Cited by 7 | Viewed by 5658

Abstract

In this work, oxidizing roasting was combined with leaching to separate copper, lead, and zinc from a concentrate obtained by bulk flotation of a low-grade ore sourced from the Jiama mining area of Tibet. The flotation concentrate contained 7.79% Cu, 22.00% Pb, 4.81% [...] Read more.

In this work, oxidizing roasting was combined with leaching to separate copper, lead, and zinc from a concentrate obtained by bulk flotation of a low-grade ore sourced from the Jiama mining area of Tibet. The flotation concentrate contained 7.79% Cu, 22.00% Pb, 4.81% Zn, 8.24% S, and 12.15% CaO; copper sulfide accounted for 76.97% of the copper, lead sulfide for 25.55% of the lead, and zinc sulfide for 67.66% of the zinc. After oxidizing roasting of the flotation concentrate, the S content in the roasting slag decreased to 0.22%, indicating that most sulfide in the concentrate was transformed to oxide, which was beneficial to leaching. The calcine was subjected to sulfuric acid leaching for separation of copper, lead, and zinc; i.e., copper and zinc were leached, and lead was retained in the residue. The optimum parameters of the leaching process were: a leaching temperature of 55 °C; sulfuric acid added at 828 kg/t calcine; a liquid:solid ratio of 3:1; and a leaching time of 1.5 h. Under these conditions, the extents of leaching of copper and zinc were 87.43% and 64.38%, respectively. Copper and zinc in the leaching solution could be further separated by electrowinning. The effects of leaching parameters on the extents of leaching of copper and zinc were further revealed by X-ray diffraction and scanning electron microscopy analysis. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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20 pages, 690 KiB

Open AccessArticle

Lipid Isolation Process and Study on Some Molecular Species of Polar Lipid Isolated from Seed of Madhuca ellitica

by Doan Lan Phuong, Tran Quoc Toan, Ly P. T. Dang, Andrey B. Imbs, Pham Quoc Long, Tran Dinh Thang, Bertrand Matthaeus, Long Giang Bach and Le Minh Bui

Processes 2019, 7(6), 375; https://doi.org/10.3390/pr7060375 - 17 Jun 2019

Cited by 6 | Viewed by 4706

Abstract

This study attempted the lipid extraction process from the seeds of Madhuca ellitica, a lipid-rich plant, and conducted a lipidomic analysis on molecular species of the obtained product. Total lipids of the crude seeds were found to contain 11.2% of polar lipids. [...] Read more.

This study attempted the lipid extraction process from the seeds of Madhuca ellitica, a lipid-rich plant, and conducted a lipidomic analysis on molecular species of the obtained product. Total lipids of the crude seeds were found to contain 11.2% of polar lipids. The major fatty acids (FAs) of the polar lipids were palmitic (16:0), stearic (18:0), oleic (18:1n-9), and linoleic (18:2n-6) acids, which amounted to 28.5, 12.5, 44.8, and 13.2% of total FAs, respectively. The content and chemical structures of individual molecular species of phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidic acid (PA), and sulfoquinovosyldiacylglycerol (SQDG) were determined by HPLC with a tandem high-resolution mass spectrometry (HRMS). The major molecular species were 18:1/18:2 PE, 16:0/18:1 PC, 18:1/18:2 PC, 16:0/18:2 PG, 16:0/18:1 PG, 16:1/18:1 PI, 16:0/18:1 PI, 18:0/18:2 PI, 16:0/18:1 PA, 18:1/18:2 PA, 16:0/18:1 SQDG, and 18:0/18:1 SQDG. The application of a tandem HRMS allows us to determine the content of each isomer in pairs of the monoisotopic molecular species, for example, 18:0/18:2 and 18:1/18:1. The evaluation of the seed polar lipid profile will be helpful for developing the potential of this tree for nutritive and industrial uses. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 841 KiB

Open AccessArticle

Yield, Phytochemical Constituents, and Antibacterial Activity of Essential Oils from the Leaves/Twigs, Branches, Branch Wood, and Branch Bark of Sour Orange (Citrus aurantium L.)

by Mohammad K. Okla, Saud A. Alamri, Mohamed Z.M. Salem, Hayssam M. Ali, Said I. Behiry, Ramadan A. Nasser, Ibrahim A. Alaraidh, Salem M. Al-Ghtani and Walid Soufan

Processes 2019, 7(6), 363; https://doi.org/10.3390/pr7060363 - 11 Jun 2019

Cited by 61 | Viewed by 6579

Abstract

In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, [...] Read more.

In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, 10, 15, 20, and 25 µL were studied for their antibacterial activity against three pathogenic bacteria, Agrobacterium tumefaciens, Dickeya solani, and Erwinia amylovora. The main EO compounds in the leaves/twigs were 4-terpineol (22.59%), D-limonene (16.67%), 4-carvomenthenol (12.84%), and linalool (7.82%). In small green branches, they were D-limonene (71.57%), dodecane (4.80%), oleic acid (2.72%), and trans-palmitoleic acid (2.62%), while in branch bark were D-limonene (54.61%), γ-terpinene (6.68%), dodecane (5.73%), and dimethyl anthranilate (3.13%), and in branch wood were D-limonene (38.13%), dimethyl anthranilate (8.13%), (-)-β-fenchol (6.83%), and dodecane (5.31%). At 25 µL, the EO from branches showed the highest activity against A. tumefaciens (IZ value of 17.66 mm), and leaves/twigs EO against D. solani and E. amylovora had an IZ value of 17.33 mm. It could be concluded for the first time that the wood and branch bark of C. aurantium are a source of phytochemicals, with D-limonene being the predominant compound in the EO, with potential antibacterial activities. The compounds identified in all the studied parts might be appropriate for many applications, such as antimicrobial agents, cosmetics, and pharmaceuticals. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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14 pages, 3015 KiB

Open AccessArticle

Purification of Amygdalin from the Concentrated Debitterizing-Water of Apricot Kernelsusing XDA-1 Resin

by Qing-An Zhang, Dong-Dong Wu and Chen-Xi Wei

Processes 2019, 7(6), 359; https://doi.org/10.3390/pr7060359 - 10 Jun 2019

Cited by 4 | Viewed by 3493

Abstract

In this study, six macroporous resins were screened on their adsorption and de-adsorption characteristics for the amygdalin in the debitterizing wastewater concentrate (DWC). The results indicate that the XDA-1 resin exerts good adsorption and de-adsorption capacities on the amygdalin. In order to further [...] Read more.

In this study, six macroporous resins were screened on their adsorption and de-adsorption characteristics for the amygdalin in the debitterizing wastewater concentrate (DWC). The results indicate that the XDA-1 resin exerts good adsorption and de-adsorption capacities on the amygdalin. In order to further confirm its feasibility, the factors affecting the capacity of adsorption and de-adsorption, and its adsorption mechanisms were also investigated. The results suggest that the optimum purification conditions were as follows: loading concentration of samples with 78.05 mg/mL, flow rate of 2 mL/min, and de-adsorption with 80% ethanol solution. The recovery rate was 88.75% and the relative content achieved 61.58% after purification by XDA-1 resin. The Freundlich model can be used to describe the entirety of the exothermic and physical adsorption processes. In summary, the conclusion which can be made from this research is that the wastewater generated from the debitterizing of apricot kernels can be well treated by resin to recycle the amygdalin and reduce its pollution to environment. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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13 pages, 2872 KiB

Open AccessArticle

Simple Preparation of Diverse Neoagaro-Oligosaccharides

by Fudi Lin, Jing Ye, Yayan Huang, Yucheng Yang and Meitian Xiao

Processes 2019, 7(5), 267; https://doi.org/10.3390/pr7050267 - 07 May 2019

Cited by 12 | Viewed by 3339

Abstract

A simple method for obtaining pure and well-defined oligosaccharides was established by hydrolyzing agar with β-agarase from Vibrio natriegens. The conditions for enzymolysis were optimized as follows: a temperature of 45 °C, a pH of 8.5, a substrate concentration of 0.3%, an [...] Read more.

A simple method for obtaining pure and well-defined oligosaccharides was established by hydrolyzing agar with β-agarase from Vibrio natriegens. The conditions for enzymolysis were optimized as follows: a temperature of 45 °C, a pH of 8.5, a substrate concentration of 0.3%, an enzyme amount of 100 U/g and an enzymolysis time of 20 h. Neoagaro-oligosaccharides with different degrees of polymerization were obtained by hydrolyzing agar with β-agarase for different lengths of time. After removing pigments using activated carbon and salts by dialyzing, the enzyme hydrolysis solution was separated with Bio-Gel P2 column chromatography. Neoagaro-oligosaccharides with different degrees of polymerization were acquired. By comparing with authentic standard substances, along with further confirmation by FTIR, MS and NMR, structures of the purified neoagaro-oligosaccharides were identified as neoagarobiose (NA2), neoagaroteraose (NA4), neoagarohexaose (NA6), neoagarooctaose (NA8), neoagaro-decaose (NA10) and neoagarododecaose (NA12) with purities of more than 97.0%. The present study established a method for the preparation of various neoagaro-oligosaccharides that may be of great significance for further study of their bioactivities. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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9 pages, 1066 KiB

Open AccessArticle

A Process for the Separation of Noble Metals from HCl Liquor Containing Gold(III), Palladium(II), Platinum(IV), Rhodium(III), and Iridium(IV) by Solvent Extraction

by Wei Dong Xing and Man Seung Lee

Processes 2019, 7(5), 243; https://doi.org/10.3390/pr7050243 - 26 Apr 2019

Cited by 18 | Viewed by 8720

Abstract

The demand for noble metals is increasing, owing to their excellent chemical and physical properties. In order to meet the demand, the recovery of noble metals with high purity from diverse secondary resources, which contain small amounts of noble metals, is of immense [...] Read more.

The demand for noble metals is increasing, owing to their excellent chemical and physical properties. In order to meet the demand, the recovery of noble metals with high purity from diverse secondary resources, which contain small amounts of noble metals, is of immense value. In this work, the possibility of the separation of Au(III), Pd(II), Pt(IV), Rh(III), and Ir(IV) by solvent extraction from a synthetic HCl solution is investigated. Only Au(III) was selectively extracted by Cyanex 272 in the HCl concentration range from 0.5 M to 9 M, leaving the other metal ions in the raffinate. The loaded Au(III) in Cyanex 272 was efficiently stripped by (NH₂)₂CS. The other four noble metals were sequentially separated on the basis of the procedures reported in the previous work. The mass balance showed that about 98% of each metal, except Pt(IV), was recovered by the proposed process. An efficient process for the recovery of the five noble metal ions from the HCl leaching solution of secondary resources containing these metals can be developed. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 1231 KiB

Open AccessArticle

Antifungal and Antibacterial Activities of Musa paradisiaca L. Peel Extract: HPLC Analysis of Phenolic and Flavonoid Contents

by Said I. Behiry, Mohmmad K. Okla, Saud A. Alamri, Mervat EL-Hefny, Mohamed Z. M. Salem, Ibrahim A. Alaraidh, Hayssam M. Ali, Salem M. Al-Ghtani, José C. Monroy and Abdelfattah Z. M. Salem

Processes 2019, 7(4), 215; https://doi.org/10.3390/pr7040215 - 15 Apr 2019

Cited by 66 | Viewed by 19636

Abstract

In the present study, Melia azedarach wood samples that were treated with the methanolic extract of Musa paradisiaca L. peels were evaluated for their antibacterial and antifungal activities against Agrobacterium tumefaciens, Dickeya solani, Erwinia amylovora, Pseudomonas cichorii, Serratia pylmuthica, [...] Read more.

In the present study, Melia azedarach wood samples that were treated with the methanolic extract of Musa paradisiaca L. peels were evaluated for their antibacterial and antifungal activities against Agrobacterium tumefaciens, Dickeya solani, Erwinia amylovora, Pseudomonas cichorii, Serratia pylmuthica, Fusarium culmorum, and Rhizoctonia solani. The strongest antibacterial activity was only found against A. tumefaciens (inhibition zone 90 mm), while the other bacterial strains showed resistance to wood that was treated with the extract. Potential antifungal activity against F. culmorum and R. solani was observed; the mycelial growth inhibition percentages reached 68.88% and 94.07%, respectively, in wood samples that were treated with the 3% methanolic extract of M. paradisiaca peel. HPLC analysis demonstrated the presence of seven phenolic compounds and three flavonoid compounds, as their peaks were matched with the standard compounds in a HPLC analysis. The major constituents of phenolic and flavonoid compounds in mg/100 g dry extract (DE) were ellagic acid (16.19), gallic acid (7.73), rutin (973.08), myricetin (11.52), and naringenin (8.47). The results demonstrated the potential effects of banana peel extract as a natural compound that can protect wood from molds while in use. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 1891 KiB

Open AccessArticle

Green Synthesis of Silver Nanoparticles Using Bilberry and Red Currant Waste Extracts

by Antonio Zuorro, Annalaura Iannone, Stefano Natali and Roberto Lavecchia

Processes 2019, 7(4), 193; https://doi.org/10.3390/pr7040193 - 03 Apr 2019

Cited by 62 | Viewed by 5345

Abstract

The production of silver nanoparticles (Ag-NPs) from bilberry waste (BW) and red currant waste (RCW) extracts was studied. Red fruit extracts were obtained by treating BW and RCW with aqueous ethanol (50% v/v) at 40 °C. The formation of nanoparticles [...] Read more.

The production of silver nanoparticles (Ag-NPs) from bilberry waste (BW) and red currant waste (RCW) extracts was studied. Red fruit extracts were obtained by treating BW and RCW with aqueous ethanol (50% v/v) at 40 °C. The formation of nanoparticles was monitored spectrophotometrically by measuring the intensity of the surface plasmon resonance band (SPR) of silver. The effects of temperature (20–60 °C) and pH (8–12) on the reaction kinetics and on the properties of Ag-NPs were investigated. Characterization by XRD and dynamic light scattering (DLS) techniques showed that Ag-NPs were highly crystalline, with a face-centered cubic structure and a hydrodynamic diameter of 25–65 nm. The zeta potential was in the range of −35.6 to −20.5 mV. Nanoparticles obtained from BW were slightly smaller and more stable than those from RCW. A kinetic analysis by the initial-rate method showed that there was an optimum pH, around 11, for the production of Ag-NPs. Overall, the results obtained suggest that BW and RCW can be advantageously used as a source of reducing and stabilizing agents for the green synthesis of Ag-NPs. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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17 pages, 1552 KiB

Open AccessArticle

Optimal Ultrasound-Assisted Process Extraction, Characterization, and Functional Product Development from Flaxseed Meal Derived Polysaccharide Gum

by Muhammad Nadeem Akhtar, Zarina Mushtaq, Nazir Ahmad, Muhammad Kamran Khan, Muhammad Haseeb Ahmad, Abdullah Ijaz Hussain and Muhammad Imran

Processes 2019, 7(4), 189; https://doi.org/10.3390/pr7040189 - 02 Apr 2019

Cited by 22 | Viewed by 4919

Abstract

Flaxseed (Linum usitatissimum L.) has several health-promoting applications as dietary food ingredient supplementation, owing to presence of high quality of oil, polyunsaturated fatty acids, high dietary fiber and protein contents. The presence of different anti-nutritional components, for example cyanogens (HCN) and tannins [...] Read more.

Flaxseed (Linum usitatissimum L.) has several health-promoting applications as dietary food ingredient supplementation, owing to presence of high quality of oil, polyunsaturated fatty acids, high dietary fiber and protein contents. The presence of different anti-nutritional components, for example cyanogens (HCN) and tannins in meal, limits its application for food purposes. The study was conducted to observe the effect of ultrasound-assisted extraction on polysaccharide gums (PSG) yield using response surface methodology. The selected variables were sonication temperature (°C), water to meal ratio, sonication amplitude level (%), sonication pH, and sonication time (min). Ultrasound-assisted extraction significantly reduced the anti-nutritional components like HCN and tannins. The extracted PSG yield from partially defatted flaxseed meal (PDFM) samples varied to a minimum of 7.24% to a maximum of 11.04% when extraction temperature (°C) and amplitude level (%) varied from −1 to +1 and keeping all other variables constant at mean value. Physiochemical and functional properties of extracted PSG were studied. Yoghurt with different treatment combinations were prepared by supplementing flaxseed-derived PSG as stabilizer ranging from 0.25% to 1.5%, keeping baseline samples without PSG as control. Functional properties of PSG-supplemented yoghurt such as pH, syneresis, and viscosity were determined to assess the influence of PSG supplementation on yoghurt quality. In the organoleptic behavior of PSG-supplemented yoghurt, no adverse effect on the flavor have been observed, but the textural properties vary significantly among different treatments. Overall, the acceptability of 1% PSG-supplemented yoghurt was significantly higher than other treatments. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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22 pages, 2138 KiB

Open AccessArticle

Comparative Evaluation of Selected Biological Methods for the Removal of Hydrophilic and Hydrophobic Odorous VOCs from Air

by Milena Gospodarek, Piotr Rybarczyk, Bartosz Szulczyński and Jacek Gębicki

Processes 2019, 7(4), 187; https://doi.org/10.3390/pr7040187 - 01 Apr 2019

Cited by 49 | Viewed by 5464

Abstract

Due to increasingly stringent legal regulations as well as increasing social awareness, the removal of odorous volatile organic compounds (VOCs) from air is gaining importance. This paper presents the strategy to compare selected biological methods intended for the removal of different air pollutants, [...] Read more.

Due to increasingly stringent legal regulations as well as increasing social awareness, the removal of odorous volatile organic compounds (VOCs) from air is gaining importance. This paper presents the strategy to compare selected biological methods intended for the removal of different air pollutants, especially of odorous character. Biofiltration, biotrickling filtration and bioscrubbing technologies are evaluated in terms of their suitability for the effective removal of either hydrophilic or hydrophobic VOCs as well as typical inorganic odorous compounds. A pairwise comparison model was used to assess the performance of selected biological processes of air treatment. Process efficiency, economic, technical and environmental aspects of the treatment methods are taken into consideration. The results of the calculations reveal that biotrickling filtration is the most efficient method for the removal of hydrophilic VOCs while biofilters enable the most efficient removal of hydrophobic VOCs. Additionally, a simple approach for preliminary method selection based on a decision tree is proposed. The presented evaluation strategies may be especially helpful when considering the treatment strategy for air polluted with various types of odorous compounds. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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17 pages, 2775 KiB

Open AccessArticle

Novel Deep Eutectic Solvent Based on Levulinic Acid and 1,4-Butanediol as an Extraction Media for Bioactive Alkaloid Rutaecarpine

by Yue-Yue Si, Shi-Wei Sun, Kun Liu, Yang Liu, Hai-Lin Shi, Ke Zhao, Jin Wang and Wei Wang

Processes 2019, 7(3), 171; https://doi.org/10.3390/pr7030171 - 24 Mar 2019

Cited by 17 | Viewed by 4674

Abstract

Deep eutectic solvents (DESs) are increasingly receiving interest as a new type of green and sustainable alternative to hazardous organic solvents. In this work, a novel DES based on levulinic acid (La) and 1,4-butanediol (Buta) as an extraction media was developed for extracting [...] Read more.

Deep eutectic solvents (DESs) are increasingly receiving interest as a new type of green and sustainable alternative to hazardous organic solvents. In this work, a novel DES based on levulinic acid (La) and 1,4-butanediol (Buta) as an extraction media was developed for extracting the bioactive alkaloid rutaecarpine from the unripe fruits of Tetradium ruticarpum. 24 different DESs consisting of choline chloride, betaine, sugar alcohols, organic acids, amides, and sugars were prepared and tailored to test their extraction efficiency. After initial screening, a hydrophilic DES composed of La and Buta with 1:0.5 molar ratio containing 25% water was tailored for the highest extraction efficiency, followed by the optimizations of molar ratio and water content. The interaction between the molecules of La-Buta DES was investigated by nuclear magnetic resonance spectroscopy in order to confirm its deep eutectic supermolecular structure feature. The extraction conditions were optimized by single-factor experiments, including extraction temperature, extraction time, and solid-liquid ratio. The developed La-Buta DES extraction procedure was successfully applied for the analysis of rutaecarpine in Chinese patent medicines containing the unripe fruits of T. ruticarpum. The excellent property of La-Buta DES indicated its potential as a promising green solvent instead of conventional organic solvent for the extraction of rutaecarpine from the unripe fruits of T. ruticarpum, and that it can used as a sustainable and safe extraction media for other applications. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 1284 KiB

Open AccessArticle

Water–Organic Solvent Extraction of Phenolic Antioxidants from Brewers’ Spent Grain

by Antonio Zuorro, Annalaura Iannone and Roberto Lavecchia

Processes 2019, 7(3), 126; https://doi.org/10.3390/pr7030126 - 01 Mar 2019

Cited by 61 | Viewed by 6687

Abstract

Brewers’ spent grain (BSG) is the most abundant by-product of the brewing process. BSG is currently disposed of or used as a supplement for animal feed, although it contains significant amounts of bioactive compounds of great interest to the pharmaceutical, cosmetic and food [...] Read more.

Brewers’ spent grain (BSG) is the most abundant by-product of the brewing process. BSG is currently disposed of or used as a supplement for animal feed, although it contains significant amounts of bioactive compounds of great interest to the pharmaceutical, cosmetic and food sectors. In this study we investigate the feasibility of using a simple solvent extraction procedure to recover phenolic antioxidants from BSG. Acetone–water and ethanol–water mixtures were used as extraction solvents. Phenolic extracts obtained by treatment of BSG with the two solvent systems were characterized in terms of total phenolics and antioxidant activity. For both systems, the extraction yield was maximum at 60% (v/v) organic solvent concentration. At all solvent compositions, mixtures containing acetone provided higher extraction yields. As suggested by the strong correlation between the antioxidant activity of BSG extracts and their phenolic content, the antioxidant capacity of the extracts can be mainly attributed to polyphenols. Overall, the obtained results strongly support the exploitation of BSG as a source of phenolic antioxidants and the possibility of recovering them by a mild and green extraction process. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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12 pages, 2602 KiB

Open AccessArticle

Effects of Caustic Extraction on Properties of Viscose Grade Dissolving Pulp

by Cindy Friebel, Robert H. Bischof, Gabriele Schild, Karin Fackler and Ireen Gebauer

Processes 2019, 7(3), 122; https://doi.org/10.3390/pr7030122 - 27 Feb 2019

Cited by 13 | Viewed by 4636

Abstract

Viscose, a cellulose-based commodity fibre, is produced by pulping and bleaching of wood, yielding a high quality “dissolving pulp” which is then spun. During pulping and bleaching, effective hemicellulose extraction is required to allow fibre production. We present a design of experiments (DoE) [...] Read more.

Viscose, a cellulose-based commodity fibre, is produced by pulping and bleaching of wood, yielding a high quality “dissolving pulp” which is then spun. During pulping and bleaching, effective hemicellulose extraction is required to allow fibre production. We present a design of experiments (DoE) approach to optimise caustic extraction in a total chlorine free (TCF) bleaching sequence (O-CE-Z-P) of beech wood sulphite pulp. Temperature and sodium hydroxide concentration were varied to identify highest xylan extraction yield, and a maximum xylan removal of 83% was achieved at 20 °C and 120 g/L NaOH. Additionally, caustic extraction conditions were derived from the DoE model that led to pulps with high yield, high alpha cellulose content or uniform cellulose molecular weight distribution. Pulps from verification experiments exhibited good reactivity in viscose application tests. Hence, the presented O-CE-Z-P bleaching sequence can be considered as suitable for integrated viscose fibre production. We assume that the presented caustic extraction model will be useful for pulp and biorefinery researchers who work on caustic biorefinery processes involving hardwood feedstocks. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 3735 KiB

Open AccessArticle

Purification of Flavonoids from Mulberry Leaves via High-Speed Counter-Current Chromatography

by Pian Zhang, Kang-Ling Zhu, Jun Zhang, Yan Li, Heng Zhang and Yan Wang

Processes 2019, 7(2), 91; https://doi.org/10.3390/pr7020091 - 13 Feb 2019

Cited by 7 | Viewed by 4206

Abstract

In order to obtain high-purity flavonoid products, the extracts from mulberry leaves were separated and purified via high-speed counter-current chromatography (HSCCC). Moreover, the product was detected via high-performance liquid chromatography (HPLC). The characteristic absorption wavelength of the rutin standard for HSCCC detection and [...] Read more.

In order to obtain high-purity flavonoid products, the extracts from mulberry leaves were separated and purified via high-speed counter-current chromatography (HSCCC). Moreover, the product was detected via high-performance liquid chromatography (HPLC). The characteristic absorption wavelength of the rutin standard for HSCCC detection and HPLC analysis at 257 nm was tested by ultraviolet scanning analysis. The effect of solvent systems and mobile phase flow rate on the separation efficiency were then researched. Finally, the solvent system of V(ethyl acetate):V(n-butanol):V(water) = 4:1:5 was selected as the operating system for HSCCC. This work theoretically analyzed the impact of the molecular structure and polarity of flavonoids on the choice of solvent systems. The results showed that the mobile phase flow rate had a great influence on the separation efficiency. Furthermore, the separation efficiency increased as the mobile phase flow rate decreased. When the mobile phase flow rate was 5 mL/min, the peak time for flavonoids was 140 min, the retention of the stationary phase was 56.4%, and the purity of the product reached 93.8%. The results of this study greatly improved the purity of flavonoids in mulberry leaf and provided a strong support for the separation and purification of mulberry leaf extract. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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11 pages, 3996 KiB

Open AccessArticle

Evaluation of Conditions Affecting Properties of Gac (Momordica Cocochinensis Spreng) Oil-Loaded Solid Lipid Nanoparticles (SLNs) Synthesized Using High-Speed Homogenization Process

by Huynh Cang Mai, Thai Sa Vin Nguyen, Thi Hong Nhan Le, Duy Chinh Nguyen and Long Giang Bach

Processes 2019, 7(2), 90; https://doi.org/10.3390/pr7020090 - 12 Feb 2019

Cited by 24 | Viewed by 4018

Abstract

In this study, we attempted the preparation of gac oil-loaded solid lipid nanoparticles (SLNs) by the high-speed homogenization method using Naterol SE solid lipid, a cosmetic self-emulsifying base, and surfactant and investigated the effects of different conditions on the characteristics of the resulting [...] Read more.

In this study, we attempted the preparation of gac oil-loaded solid lipid nanoparticles (SLNs) by the high-speed homogenization method using Naterol SE solid lipid, a cosmetic self-emulsifying base, and surfactant and investigated the effects of different conditions on the characteristics of the resulting nanoparticles. The suspensions containing 5% active agents (gac-oil, w/w) were dispersed in a surfactant concentration of 5% (w/w) (Span 80:Tween 80 ratio of 28:72 w/w) and 2.5% (w/w) of solid lipid (Naterol SE) concentration. Suitable conditions for hot homogenization were 13,000 rpm, 60 min and 60 °C for speed, time and temperature, respectively. The suitable conditions for the subsequent cold homogenization were 25 min of homogenization time and 5 °C of temperature. The results showed that the mean size of SLNs-gac oil was 107 nm (measured by laser diffraction spectrometry, LDS), and dried size of SLNs-gac oil ranged from 50 to 80 nm (measured by transmission electron microscope, TEM). In addition, the study investigated the impact of gac oil content on the particle size of SLNs-gac oil and its stability under different storage conditions of UV radiation and storage temperature. At high storage temperatures, the color changes (ΔE) of the samples were more profound in comparison to that at the low storage temperature. The ΔE value of the blank sample (SLN-FREE gac-oil) was higher than that of the Gac oil-loaded SLNs samples (SLN-gac oil). Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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16 pages, 1592 KiB

Open AccessFeature PaperArticle

Phytochemical Content of Melissa officinalis L. Herbal Preparations Appropriate for Consumption

by Vassiliki T. Papoti, Nikolaos Totomis, Aikaterini Atmatzidou, Kyriaki Zinoviadou, Anna Androulaki, Dimitris Petridis and Christos Ritzoulis

Processes 2019, 7(2), 88; https://doi.org/10.3390/pr7020088 - 12 Feb 2019

Cited by 21 | Viewed by 5716

Abstract

Melissa Officinalis L. (MOL) domestic preparations appropriate for consumption were studied by monitoring content in Na, K, Ca, Li, phenolic bioactives (total phenols, hydroxycinnamic acid derivatives and flavonols), and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl radical inhibition (DPPH) and ferric reducing ability (FRAP)). The effects of [...] Read more.

Melissa Officinalis L. (MOL) domestic preparations appropriate for consumption were studied by monitoring content in Na, K, Ca, Li, phenolic bioactives (total phenols, hydroxycinnamic acid derivatives and flavonols), and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl radical inhibition (DPPH) and ferric reducing ability (FRAP)). The effects of practice applied, material to solvent ratio, time of preparation, and solvent were studied. MOL decoctions and infusions, commonly prepared at home, were better or of equal nutritional value to preparations upon ultrasounds or maceration concerning the studied parameters. Aqueous MOL preparations were richer in total phenols (704–1949 mg per 250 mL) and the examined macroelements (1.1–2.9, 30.5–288.4 and 50.1–176.1 mg Na, K and Ca per 250 mL, respectively) and showed better antioxidant activity compared to ethanol counterparts. The 25% w/v hydroethanolic MOL preparations, suitable for consumption, presented a significant content in phenolic antioxidants and in the examined minerals, too. MOL infusions were significantly richer in total phenols with respective chamomile and olive leaf ones, comparatively examined. Overall acceptance scores of aqueous MOL preparations indicated that bitterness has to be masked for efficient reception by the consumers. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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9 pages, 2149 KiB

Open AccessArticle

Effect of Supercritical Fluid Extraction Process on Chemical Composition of Polianthes tuberosa Flower Extracts

by Javier C. Fragoso-Jiménez, Ernesto Tapia-Campos, Mirna Estarron-Espinosa, Rodrigo Barba-Gonzalez, Ma. Claudia Castañeda-Saucedo and Gustavo A. Castillo-Herrera

Processes 2019, 7(2), 60; https://doi.org/10.3390/pr7020060 - 23 Jan 2019

Cited by 8 | Viewed by 5759

Abstract

Supercritical fluid extracts from flowers of Polianthes tuberosa var. double were ob tained using carbon dioxide as a solvent. Yield extract obtained was 2.5%. The effects of the pressure process (18 MPa, 28 MPa, and 38 MPa) and temperature process (313 K, 323 [...] Read more.

Supercritical fluid extracts from flowers of Polianthes tuberosa var. double were ob tained using carbon dioxide as a solvent. Yield extract obtained was 2.5%. The effects of the pressure process (18 MPa, 28 MPa, and 38 MPa) and temperature process (313 K, 323 K, and 333 K) on the volatile composition of tuberose flowers extracts were evaluated, and a significant variation in chemical composition was found. Characteristic compounds of tuberose as methyl isoeugenol, benzyl benzoate, methyl anthranilate, pentacosene, and heptacosene were obtained mainly at 18 MPa and 333 K process conditions, and could be used in the perfume or fragrance industry. Components such as geraniol, farnesol, and methyl eugenol were also obtained, these extracts could be used in the development of cosmeceutical products. This work allowed to identification of the chemical composition profile and evaluation of the changes in tuberose extracts due to the extraction process. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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15 pages, 6520 KiB

Open AccessArticle

The Study on Extraction Process and Analysis of Components in Essential Oils of Black Pepper (Piper nigrum L.) Seeds Harvested in Gia Lai Province, Vietnam

by Thien Hien Tran, Le Ke Ha, Duy Chinh Nguyen, Tan Phat Dao, Le Thi Hong Nhan, Dai Hai Nguyen, Trinh Duy Nguyen, Dai-Viet N. Vo, Quoc Toan Tran and Long Giang Bach

Processes 2019, 7(2), 56; https://doi.org/10.3390/pr7020056 - 22 Jan 2019

Cited by 81 | Viewed by 16149

Abstract

Black pepper (Piper nigrum L.) is a tropical crop with extensive medicinal potential in ethnomedicine and nutraceutical applications. The essential oil of black pepper finds wide applications in inhabitation of respiratory infections and soothing of muscular pains due to its warming and [...] Read more.

Black pepper (Piper nigrum L.) is a tropical crop with extensive medicinal potential in ethnomedicine and nutraceutical applications. The essential oil of black pepper finds wide applications in inhabitation of respiratory infections and soothing of muscular pains due to its warming and energizing property. The pungent bioactive piperine is responsible for this function, and therefore, efficient technology is required for an optimal extraction process of this compound. In the present article, we have developed a procedure for extracting black pepper essential oil from Vietnam, optimizing conditions that affect the extraction process. The effect of process parameters, namely material size, preservation method, the concentration of sodium chloride, the concentration of soak time, the ratio of material to water, temperature extraction, time extraction on the extraction yield, and relative efficiency were investigated. Results demonstrated that 20 g of black pepper milled with a mesh size of 160 obtained 0.48 g of essential oil (2.4%) at a raw material to water ratio of 1/21 (g/mL) at 150 °C in a time of 5.2 h. GC-MS (Gas chromatography–mass spectrometry) spectra showed that 3-carene (29.21%), D-limonene (20.94%), caryophyllene (15.05%), and β-pinene (9.77%) were present as major components. These results suggested that the essential oil extracted from Vietnamese black pepper is applicable in the manufacturing processes of insecticides and air deodorizers. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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9 pages, 2457 KiB

Open AccessArticle

Pilot Plant Data Assessment in Anaerobic Digestion of Organic Fraction of Municipal Waste Solids

by Massimo Migliori, Enrico Catizzone, Girolamo Giordano, Adolfo Le Pera, Miriam Sellaro, Alessandro Lista, Giuseppe Zanardi and Luciano Zoia

Processes 2019, 7(1), 54; https://doi.org/10.3390/pr7010054 - 21 Jan 2019

Cited by 25 | Viewed by 5156

Abstract

In this paper, a preliminary study of anaerobic digestion of organic fraction of municipal solid wastes (OFMSW) in presented with the aim to compare the performances of both wet- and dry-type reactors. The treatment of OFMSW via anaerobic digestion (AD) producing biogas is [...] Read more.

In this paper, a preliminary study of anaerobic digestion of organic fraction of municipal solid wastes (OFMSW) in presented with the aim to compare the performances of both wet- and dry-type reactors. The treatment of OFMSW via anaerobic digestion (AD) producing biogas is a process that is receiving a growing interest because two different needs can be coupled: the request of sustainable municipal waste treatments and increasing demand renewable energy. This paper aims to offer experimental results comparing batch test and continuous experimental reactors under different conditions of humidity and solid content. Results show that both the investigated configurations may be used for converting OFMSW into a high quality biogas and that the increase of dry matter in the continuous process still allows to achieve significant biogas production rates. A slight reduction of the methane content was observed (less than 5% relative) that can be also related to the change in the level of volatile fatty acids. These results are very promising in supporting the possibility of operating an industrial scale plant with a dry-process without affecting the system performance. Full article

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18 pages, 4255 KiB

Open AccessArticle

Ultrasonic-Assisted Extraction and Swarm Intelligence for Calculating Optimum Values of Obtaining Boric Acid from Tincal Mineral

by Bahdisen Gezer and Utku Kose

Processes 2019, 7(1), 30; https://doi.org/10.3390/pr7010030 - 10 Jan 2019

Cited by 2 | Viewed by 4126

Abstract

The objective of this study is to focus on boric acid extraction from the mineral tincal, in order to determine the optimum conditions thanks to the ultrasonic-assisted extraction (UAE) technique (with the response surface methodology (RSM) for the first time), and artificial intelligence [...] Read more.

The objective of this study is to focus on boric acid extraction from the mineral tincal, in order to determine the optimum conditions thanks to the ultrasonic-assisted extraction (UAE) technique (with the response surface methodology (RSM) for the first time), and artificial intelligence based swarm intelligence. Characterization of the tincal were done by using thermo-gravimetric assay (TG-DTA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. In detail, a central composite design (CCD) was used for determining the effects of different solvent/solid ratios, pH, extraction time, and extraction temperature on the yield, which was determined by the conductometric method. The optimum values regarding the best extraction process was calculated by using five different swarm intelligence techniques: Particle swarm optimization (PSO), cuckoo search (CS), genetic algorithms (GA), Differential evolution (DE), and the vortex optimization algorithm (VOA). In the study content, technical details regarding to background and applied experimental processes are given and the findings pointing an approximate 85–92% boron extraction from tincal ore are discussed generally. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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13 pages, 1763 KiB

Open AccessArticle

A Green Process for the Extraction and Purification of Hesperidin from Mexican Lime Peel (Citrus aurantifolia Swingle) that is Extendible to the Citrus Genus

by J. Daniel Padilla de la Rosa, Priscilla Ruiz-Palomino, Enrique Arriola-Guevara, Jorge García-Fajardo, Georgina Sandoval and Guadalupe M. Guatemala-Morales

Processes 2018, 6(12), 266; https://doi.org/10.3390/pr6120266 - 15 Dec 2018

Cited by 30 | Viewed by 7965

Abstract

The processing of Mexican limes generates great amounts of peel as a by-product. Lime peel is mainly rich in the flavonoid hesperidin, whose bioactivity is oriented mainly to cardiovascular diseases and cancer. The purpose of this work was to develop a green process [...] Read more.

The processing of Mexican limes generates great amounts of peel as a by-product. Lime peel is mainly rich in the flavonoid hesperidin, whose bioactivity is oriented mainly to cardiovascular diseases and cancer. The purpose of this work was to develop a green process for the extraction and purification of hesperidin from Mexican lime peel. The extraction of hesperidin was investigated on a laboratory scale by varying the solvent composition and the solid-to-solvent ratio, and then scaling this process (volume: 20 L). Next, a purification process using adsorption resins was assessed: first through static tests to determine the adsorption efficiency with two resins (FPX66, EXA118), and then on a packed column with 80 mL of resin at 25 °C. Lab-scale extraction showed that the best conditions were a solid-to-solvent ratio of 0.33 g/mL and 60% ethanol. After using these conditions at pilot scale and concentrating the solution, the hesperidin content of the extract was 0.303 mg/mL. Through static tests, higher adsorption efficiencies were achieved with the EXA-118 resin and diluted extract (4:6 ratio with 10% dimethylsulfoxide, (DMSO)). Finally, the purification process on a packed column from the diluted extract (hesperidin concentration of 0.109 mg/mL) had a mean recovery efficiency of almost 90%. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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Review

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16 pages, 1398 KiB

Open AccessReview

Overview of Alternative Ethanol Removal Techniques for Enhancing Bioethanol Recovery from Fermentation Broth

by Hamid Zentou, Zurina Zainal Abidin, Robiah Yunus, Dayang Radiah Awang Biak and Danil Korelskiy

Processes 2019, 7(7), 458; https://doi.org/10.3390/pr7070458 - 17 Jul 2019

Cited by 38 | Viewed by 18573

Abstract

This study aims at reviewing the alternative techniques for bioethanol recovery, highlighting its advantages and disadvantages, and to investigate the technical challenges facing these alternatives to be widely used. The findings showed that the integration of these techniques with the fermentation process did [...] Read more.

This study aims at reviewing the alternative techniques for bioethanol recovery, highlighting its advantages and disadvantages, and to investigate the technical challenges facing these alternatives to be widely used. The findings showed that the integration of these techniques with the fermentation process did not meet a large acceptance in the industrial sector. The majority of conducted studies were mainly focusing on ethanol recovery from aqueous standard solution rather than the investigation of these techniques performance in fermentation-separation coupled system. In this context, pervaporation has received more attention as a promising alternative to distillation. However, some challenges are facing the integration of these techniques in the industrial scale as the fouling problem in pervaporation, the toxicity of solvent in liquid extraction, energy consumption in vacuum fermentation. It was also found that there is a lack of the technical economic analysis for these techniques which may limit the spread of its application in the large scale. Currently, hybrid systems integrating distillation with other alternative techniques are considered as an innovative solution to reduce the high cost of the distillation process and the low separation efficiency of the alternatives techniques. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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14 pages, 1892 KiB

Open AccessFeature PaperReview

The Flotation Process Can Go Green

by George Z. Kyzas and Kostas A. Matis

Processes 2019, 7(3), 138; https://doi.org/10.3390/pr7030138 - 06 Mar 2019

Cited by 40 | Viewed by 5921

Abstract

In today’s world of environmental strain, wastewater treatment has become a, more or less, conventional application of flotation—as for instance, in the oil, food, or chemical industries, and in potable water treatment. In this paper, different flotation methods (such as ion, adsorbing colloid, [...] Read more.

In today’s world of environmental strain, wastewater treatment has become a, more or less, conventional application of flotation—as for instance, in the oil, food, or chemical industries, and in potable water treatment. In this paper, different flotation methods (such as ion, adsorbing colloid, and adsorptive flotation, including biosorption) and techniques will be reviewed; and, in order to explain them further, several applications of these from the laboratory (General and Inorganic Chemical Technology) at Aristotle University of Thessaloniki, Greece (AUTh) will be presented and analyzed, with the main focus on sustainability. The application of flotation as a separation process, when applied in pollution control or during water treatment, was often criticized due to the possible toxicity of the applied collectors; however, the use of biosurfactants may alleviate this concern and enhance its further acceptability. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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Other

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27 pages, 6118 KiB

Open AccessFeature PaperProject Report

Applied Cleaning Methods of Oil Residues from Industrial Tanks

by Alexandros Chrysalidis and George Z. Kyzas

Processes 2020, 8(5), 569; https://doi.org/10.3390/pr8050569 - 11 May 2020

Cited by 11 | Viewed by 36903

Abstract

The oil industry is facing a major problem with the large amount of oil residue generated in the tanks that store and process crude oil or its products. Research has shown that the residues of petroleum sludge, which according to a sample from [...] Read more.

The oil industry is facing a major problem with the large amount of oil residue generated in the tanks that store and process crude oil or its products. Research has shown that the residues of petroleum sludge, which according to a sample from the Azzawiya oil refinery in Libya mainly consist of oil, water and solid residues in 42.8%, 2.9% and 55.2% respectively, result in the alteration of the product quality and reduced capacity of the tanks. The solution for this problem as well as the need for inspection and maintenance requires the removal of this oil sludge and the internal cleaning of the tanks. This report aims to review the applied clean-up methods available in the world market and to identify the most efficient, safest, most economical and most environmentally friendly cleaning process. It must be noted that until now, there is not any published work which presents the applied techniques. To accomplish this goal, a total of five manual, automatic and robotic cleaning systems were analyzed and evaluated according to their advantages and disadvantages. The results show that the MEGAMACS with sludge extractor automatic cleaning system with an output of 14.8 m³/h is the fastest cleaning system, while the MARTin where the presence of people inside the tank is not necessary at any stage is the safest. In terms of cleaning costs and environmental impact, the automated BLABO, COW and MEGAMACS systems as well as the MARTin robotic system are the most economical and environmentally friendly due to the closed cleaning circuit and the ability to recover up to 95% of the oil from the sludge, which is returned to the customer and the earnings cover the costs of cleaning. The conclusion drawn is that the current need in the oil industry, in the field of tank cleaning, is the use of high-efficiency automatic or robotic cleaning methods, which aim to reduce the tank downtime, without the need for staff entrance into a permit-required confined space and with the ability to recover up to 100% of the hydrocarbons present in the composition of the sludge. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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16 pages, 2832 KiB

Open AccessCase Report

Application of Supergravity Technology in a TEG Dehydration Process for Offshore Platforms

by Hongfang Lu, Guoguang Ma, Mohammadamin Azimi and Lingdi Fu

Processes 2019, 7(1), 43; https://doi.org/10.3390/pr7010043 - 15 Jan 2019

Cited by 1 | Viewed by 5272

Abstract

In the dehydration process of offshore natural gas production, due to the site limitation of the platform, if the conventional triethylene glycol (TEG) dehydration process is employed, the size of the absorption tower is usually small. However, in the case of fluctuations in [...] Read more.

In the dehydration process of offshore natural gas production, due to the site limitation of the platform, if the conventional triethylene glycol (TEG) dehydration process is employed, the size of the absorption tower is usually small. However, in the case of fluctuations in raw material gas and large gas production, it is easy to cause a large loss of TEG and a flooding event, resulting in the water dew point of natural gas not meeting the requirements. Therefore, combined with the dehydration process of TEG and supergravity technology, a new dehydration process of natural gas suitable for offshore platforms is proposed in this paper. The principle and process of the TEG dehydration process based on supergravity technology are discussed by establishing a mass transfer model. The laboratory experiment of the new process is carried out, and the effects of TEG flow rate, super-gravity packed bed rotation speed, and gas flow rate on the air dew point are obtained. By studying the dewatering balance of the rotating packed bed in the improved process, it is proved that the dewatering performance of the high gravity machine (Higee) is much better than that of the ordinary tower dewatering equipment. Through field experiments, the dewatering effect of continuous operation and sudden changes in working conditions is obtained, indicating that the Higee can completely replace the traditional tower equipment for natural gas dehydration. Full article

(This article belongs to the Special Issue Green Separation and Extraction Processes)

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