Research

21 pages, 1239 KiB

Open AccessFeature PaperArticle

Portuguese Kelps: Feedstock Assessment for the Food Industry

by Diana Pacheco, Giuseppe Miranda, Carolina P. Rocha, Rosinda L. Pato, João Cotas, Ana M. M. Gonçalves, Sandra M. Dias Santos, Kiril Bahcevandziev and Leonel Pereira

Appl. Sci. 2021, 11(22), 10681; https://doi.org/10.3390/app112210681 - 12 Nov 2021

Cited by 5 | Viewed by 3336

Abstract

Seaweeds have been incorporated in the daily diet of several human cultures since ancient times, due to their nutritional characteristics and healthy properties. The brown seaweeds Undaria pinnatifida, Saccharina latissima, Sacchoriza polyschides, and Laminaria ochroleuca were collected in the Viana [...] Read more.

Seaweeds have been incorporated in the daily diet of several human cultures since ancient times, due to their nutritional characteristics and healthy properties. The brown seaweeds Undaria pinnatifida, Saccharina latissima, Sacchoriza polyschides, and Laminaria ochroleuca were collected in the Viana do Castelo (Portugal) bay to assess their proximate composition analysis. As a result, the algal biomass was dried, and its moisture and ash content were determined. The dried biomass was then analyzed for total nitrogen/total protein (using the Kjeldahl method), total fiber content (through fiber analyzer digestion), total lipids (in a Soxhlet apparatus), and fatty acid characterization (by gas chromatography-mass spectrometry). Apart from phosphorus, which was analyzed by spectrophotometry, the ashes were employed for mineral and trace element characterization via dry mineralization and quantified using flame atomic absorption spectrometry. Moreover, the total phenolic content was assessed spectrophotometrically by the Folin-Ciocalteu method in the algal aqueous extracts. Analyses showed that their protein concentrations ranged from 12 to 24% dry weight (DW), while lipid concentrations varied between 0.51% and 1.52% DW. Regarding the carbohydrate concentration in these seaweeds, a concentration between 48% and 60% DW was observed. The S. polyschides had the highest overall total phenolic content (6.19 × 10⁻³ g GAE/100 g of dried algae), while L. ochroleuca had the lowest amount (3.72 × 10⁻³ g GAE/100 g of dried algae). U. pinnatifida had the highest total fatty acid content (35.13 mg/g DW), whereas S. latissima presented the lowest value (22.59 mg/g DW). Significant concentrations of highly unsaturated fatty acids (HUFA) were observed in both seaweeds, with U. pinnatifida having the highest value (10.20 mg/g DW) and S. latissima the lowest content (4.81 mg/g DW). It is also highlighted that these seaweeds have a nutritional relevance as a source of essential nutrients, including nitrogen, potassium, sodium, calcium, magnesium, and iron. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

14 pages, 1974 KiB

Open AccessArticle

Starch Rich Chlorella vulgaris: High-Throughput Screening and Up-Scale for Tailored Biomass Production

by Giorgia Carnovale, Filipa Rosa, Volha Shapaval, Simona Dzurendova, Achim Kohler, Trude Wicklund, Svein Jarle Horn, Maria J. Barbosa and Kari Skjånes

Appl. Sci. 2021, 11(19), 9025; https://doi.org/10.3390/app11199025 - 28 Sep 2021

Cited by 9 | Viewed by 3653

Abstract

The use of microalgal starch has been studied in biorefinery frameworks to produce bioethanol or bioplastics, however, these products are currently not economically viable. Using starch-rich biomass as an ingredient in food applications is a novel way to create more value while expanding [...] Read more.

The use of microalgal starch has been studied in biorefinery frameworks to produce bioethanol or bioplastics, however, these products are currently not economically viable. Using starch-rich biomass as an ingredient in food applications is a novel way to create more value while expanding the product portfolio of the microalgal industry. Optimization of starch production in the food-approved species Chlorella vulgaris was the main objective of this study. High-throughput screening of biomass composition in response to multiple stressors was performed with FTIR spectroscopy. Nitrogen starvation was identified as an important factor for starch accumulation. Moreover, further studies were performed to assess the role of light distribution, investigating the role of photon supply rates in flat panel photobioreactors. Starch-rich biomass with up to 30% starch was achieved in cultures with low inoculation density (0.1 g L⁻¹) and high irradiation (1800 µmol m⁻² s⁻¹). A final large-scale experiment was performed in 25 L tubular reactors, achieving a maximum of 44% starch in the biomass after 12 h in nitrogen starved conditions. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

18 pages, 654 KiB

Open AccessFeature PaperArticle

Soybean Germination Response to Algae Extract and a Static Magnetic Field Treatment

by Katarzyna Dziergowska, Sylwia Lewandowska, Rafał Mech, Michał Pol, Jerzy Detyna and Izabela Michalak

Appl. Sci. 2021, 11(18), 8597; https://doi.org/10.3390/app11188597 - 16 Sep 2021

Cited by 6 | Viewed by 2576

Abstract

The present study examines the separate and synergistic effects of macroalgal extract and static magnetic field (SMF) on the germination of soybean seeds (Glycine max (L.) Merrill), cv. Abelina, seedling growth, chlorophyll, and carotenoids content in leaves. Algal extract was produced from [...] Read more.

The present study examines the separate and synergistic effects of macroalgal extract and static magnetic field (SMF) on the germination of soybean seeds (Glycine max (L.) Merrill), cv. Abelina, seedling growth, chlorophyll, and carotenoids content in leaves. Algal extract was produced from freshwater green macroalga (Cladophora glomerata) using ultrasound-assisted extraction. The germination tests were conducted in two stages. Firstly, different concentrations of extracts, 20%, 40%, 60%, 80%, and 100%, were applied to a paper substrate. The best results (taking into account germination percentage, seedlings length and weight, and pigments content in leaves) were observed for 20% and 80% extracts. At the same stage, germination of seeds exposed to SMF (exposure times for 3 and 12 min and magnetic inductions of 250 and 500 mT) was studied. The best developed seedlings were determined for the group treated at 3 min with a magnetic induction of 250 mT. In the final step, the simultaneous effects of 20% and 80% algal extracts and treatment with 3 min at 250 mT SMF were tested. Taking into account all the parameters, the simultaneous use of 20% extract and 3 min of 250 mT magnetic induction is recommended. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

17 pages, 2711 KiB

Open AccessArticle

Evaluation and Characterization of Alginate Extracted from Brown Seaweed Collected in the Red Sea

by Sarah H. Rashedy, Mohamed S. M. Abd El Hafez, Mahmoud A. Dar, João Cotas and Leonel Pereira

Appl. Sci. 2021, 11(14), 6290; https://doi.org/10.3390/app11146290 - 07 Jul 2021

Cited by 44 | Viewed by 6957

Abstract

Alginates are one of the most important compounds of brown seaweeds. These compounds are employed in the food area, because of their important rheological properties, such as viscosity, gelling, and stabilizing features and as dietary fiber source. In this study, five species of [...] Read more.

Alginates are one of the most important compounds of brown seaweeds. These compounds are employed in the food area, because of their important rheological properties, such as viscosity, gelling, and stabilizing features and as dietary fiber source. In this study, five species of dominant brown seaweeds were collected in the Red Sea (Padina boergesenii, Turbinaria triquetra, Hormophysa cuneiformis, Dictyota ciliolata, and Sargassum aquifolium) so as to characterize the alginate yield and its properties. The analysis demonstrated differences in the alginate yield among the seaweeds. The highest yield of alginate was recorded in the species T. triquetra (22.2 ± 0.56% DW), while the lowest content was observed in H. cuneiformis (13.3 ± 0.52% DW). The viscosity from the alginates varied greatly between the species, whereas the pH varied slightly. The alginate exhibited a moisture content between 6.4 and 13.1%, the ash content ranged between 12.3 and 20% DW, the protein reached values from 0.57 to 1.47% DW, and the lipid concentration varied from 0.3 to 3.5% DW. Thus, the phytochemical analysis demonstrated that the extracted alginates can be safely applied in the food industry. Furthermore, the alginate yield reveals the potential application of these seaweeds as a nutraceutical raw source, which can be exploited by the food industry. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

16 pages, 2126 KiB

Open AccessFeature PaperArticle

Municipal Wastewater: A Sustainable Source for the Green Microalgae Chlorella vulgaris Biomass Production

by Diana Pacheco, A. Cristina S. Rocha, Analie Garcia, Ana Bóia, Leonel Pereira and Tiago Verdelhos

Appl. Sci. 2021, 11(5), 2207; https://doi.org/10.3390/app11052207 - 03 Mar 2021

Cited by 6 | Viewed by 3754

Abstract

The need to reduce the costs associated with microalgae cultivation encouraged scientific research into coupling this process with wastewater treatment. Thus, the aim of this work was to assess the growth of Chlorella vulgaris (Chlorophyta) in different effluents from a municipal wastewater treatment [...] Read more.

The need to reduce the costs associated with microalgae cultivation encouraged scientific research into coupling this process with wastewater treatment. Thus, the aim of this work was to assess the growth of Chlorella vulgaris (Chlorophyta) in different effluents from a municipal wastewater treatment plant (WWTP), namely secondary effluent (SE) and sludge run-off (SR). Assays were performed, under the same conditions, in triplicate with 4 dilution ratios of the wastewaters (25%, 50%, 75% and 100%) with the standard culture medium bold basal medium double nitrated (BBM2N) as a control. The capability of C. vulgaris for biomass production, chlorophyll synthesis and nutrients removal in the SE and SR was evaluated. The 25% SE and 25% SR showed increased specific growth rates (0.47 and 0.55 day⁻¹, respectively) and higher biomass yields (8.64 × 10⁷ and 1.95 × 10⁷ cells/mL, respectively). Regarding the chlorophyll content, the 100% SR promoted the highest concentration of this pigment (2378 µg/L). This green microalga was also able to remove 94.8% of total phosphorus of SE, while in 50% SR, 31.2% was removed. Removal of 73.9% and 65.9% of total nitrogen in 50% and 100% SR, respectively, was also observed. C. vulgaris growth can, therefore, be maximized with the addition of municipal effluents, to optimize biomass production, while cleansing the effluents. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

24 pages, 1951 KiB

Open AccessFeature PaperArticle

Pharmacological and Cosmeceutical Potential of Seaweed Beach-Casts of Macaronesia

by Rafael Zárate, Eduardo Portillo, Sílvia Teixidó, Miguel A. A. Pinheiro de Carvalho, Nuno Nunes, Sónia Ferraz, Ana M. L. Seca, Gonçalo P. Rosa and Maria Carmo Barreto

Appl. Sci. 2020, 10(17), 5831; https://doi.org/10.3390/app10175831 - 23 Aug 2020

Cited by 20 | Viewed by 3935

Abstract

Seaweed beach-casts are a seasonal phenomenon that regularly deposits tons of algae biomass on beaches, which are usually disposed of in landfills. The present work aimed to contribute to the valorization of this biomass by studying bioactivities that reveal its potential in the [...] Read more.

Seaweed beach-casts are a seasonal phenomenon that regularly deposits tons of algae biomass on beaches, which are usually disposed of in landfills. The present work aimed to contribute to the valorization of this biomass by studying bioactivities that reveal its potential in the pharmaceutical and/or cosmeceutical industries. Methanol and ethanol extracts and fractions from 15 beach-casts biomass were tested for a range of bioactivities. Eight of the most active samples exhibit IC₅₀ values between 11.38 µg/mL and 19.28 µg/mL and selectivity indexes higher than 3.8, against NCI-H1299 (lung cancer) and T47D (breast cancer). Concerning antiaging potential, all the extracts tested presented UV protection, with SPF values above 30, like the standard sunscreen. Regarding aging-related enzymes, 24 samples were tyrosinase inhibitors exhibiting IC₅₀ values from 9.01 µg/mL to 200.09 µg/mL. Eight extracts inhibited collagenase (IC₅₀ < 248.76 µg/mL), two of them more actively than positive control EDTA (IC₅₀ = 59.26 µg/mL). In addition to UV protection, the cumulative effect of antityrosinase and anticollagenase activities shown by the samples suggest that they may play a significant role in preventing skin photoaging. The results obtained demonstrate the high potential of beach-cast seaweed biomass as sources of cosmetic bioproducts with antiaging effects, and of selective cytotoxic metabolites. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Graphical abstract

11 pages, 3472 KiB

Open AccessArticle

Influence of Medium Frequency Light/Dark Cycles on the Cultivation of Auxenochlorella pyrenoidosa

by Zhijie Chen and Bosheng Su

Appl. Sci. 2020, 10(15), 5093; https://doi.org/10.3390/app10155093 - 24 Jul 2020

Cited by 5 | Viewed by 2142

Abstract

Light (wavelength, intensity, and light/dark cycle) have been considered as one of the most important parameters for microalgae cultivation. In this paper, the effect of medium frequency intermittent light on Auxenochlorella pyrenoidosa (formerly Chlorella pyrenoidosa) cultivation was investigated. Three parameters of intermittent [...] Read more.

Light (wavelength, intensity, and light/dark cycle) have been considered as one of the most important parameters for microalgae cultivation. In this paper, the effect of medium frequency intermittent light on Auxenochlorella pyrenoidosa (formerly Chlorella pyrenoidosa) cultivation was investigated. Three parameters of intermittent light, light intensity, light/dark ratio, and light/dark cycle were employed and the influence of these parameters on the productivity of Auxenochlorella pyrenoidosa was studied. The biomass yield and growth rates were mainly affected by the light fraction and cycle time. Light with 220 μE m⁻² s⁻¹ light intensity was determined as the optimal light intensity for biomass production. At the light intensity of 420 μE m⁻² s⁻¹, the results indicated that the intermittent light improved the biomass production with larger light/dark ratio compared with the continuous light. At a lower mean light intensity over time, the intermittent light should be more suitable for biomass growth and the decrease in the light/dark ratio (L/D) will lead to a higher biomass productivity. The light/dark cycle time has little influence on the biomass yield. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

12 pages, 1305 KiB

Open AccessArticle

Biostimulant Effect of Marine Macroalgae Bioextract on Pepper Grown in Greenhouse

by Paulo Melo, Carlos Abreu, Kiril Bahcevandziev, Glácio Araujo and Leonel Pereira

Appl. Sci. 2020, 10(11), 4052; https://doi.org/10.3390/app10114052 - 11 Jun 2020

Cited by 11 | Viewed by 4138

Abstract

Marine macroalgae are a vast source of raw materials and biologically active molecules used in the pharmaceutical, cosmetic, food and agricultural industries. The search for a food free of chemical residues by consumers has led producers to use environmentally friendly and economically viable [...] Read more.

Marine macroalgae are a vast source of raw materials and biologically active molecules used in the pharmaceutical, cosmetic, food and agricultural industries. The search for a food free of chemical residues by consumers has led producers to use environmentally friendly and economically viable products as they are a source of natural compounds, forming a new and promising area of study. In this context, concentrated marine algae extracts (CMAEs) are an important alternative in this production model. This work aimed to evaluate the effects of CMAEs as biostimulants in plant metabolism, promotion of growth, development and production of pepper (Capsicum annuum L.) cultivated in a greenhouse. This work was carried out from 24 June to 30 October 2019. The number of leaves, plant length, fresh and dry plant mass, root length, root fresh and dry mass, fruit production and the metabolic performance were evaluated. The results of the stomatal conductance of pepper plants, production and biofortification were related with the levels of nutrients absorbed by the plant, which reflected the effect of the applied biostimulant. The dose that showed the most promising results was the 0.5% concentration of CMAEs. Full article

(This article belongs to the Special Issue Algae as a Nutritional and Bioactive Biomass)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Algae as a Nutritional and Bioactive Biomass

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (8 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI