Special Issue "Antioxidants and Oxidative Stability in Fats and Oils"

A special issue of Antioxidants (ISSN 2076-3921). This special issue belongs to the section "Natural and Synthetic Antioxidants".

Deadline for manuscript submissions: closed (31 May 2023) | Viewed by 10397

Special Issue Editor

Department of Characterization and Quality of Lipids, Instituto de la Grasa (CSIC), Campus Universidad Pablo de Olavide, Ctra. de Utrera km 1, E-41013 Sevilla, Spain
Interests: lipid oxidation; antioxidant mechanisms; colloidal food systems; food shelf-life and EPR spectroscopy

Special Issue Information

Dear Colleagues,

This Special Issue aims to report recent antioxidant strategies to protect edible fats and oils from lipid oxidation. The addition of effective antioxidants to prolong the shelf life of oils has been the goal of a number of investigations. Following nutritional recommendations for enhanced consumption of polyunsaturated oils, making real progress in this field is becoming increasingly necessary for the food industry. The combination of antioxidants with different functions seems to be reasonable to act in the different stages of the oxidative process. Even though such stages take place at different rates, they occur concomitantly, and an impaired flavour might develop when the global oxidation extent is still very low. In recent years, spontaneous formation of reverse micelles of amphiphilic minor components and trace water in oils has been reported to play a decisive role in lipid oxidation. Due to the elevated surface area, it is in these colloids where oxidation reactions seem to predominate. The migration of polar antioxidants to reverse micelles, as well as their concentration, appears to be the reason why polar antioxidants are more effective in oils than lipophilic antioxidants, as established in the polar paradox. Interactions of antioxidants which each other may result in synergistic effects. Therein, such interactions should take place at the colloidal interfaces, and therefore supramolecular interactions of antioxidants with reverse micelles should have an important role in preventing or retarding lipid oxidation in oils.

Dr. Joaquin Velasco
Guest Editor

Manuscript Submission Information

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Keywords

  • antioxidant
  • fats and oils
  • oxidative stability
  • reverse micelles

Published Papers (10 papers)

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Research

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Article
Effective Improvement of the Oxidative Stability of Acer truncatum Bunge Seed Oil, a New Woody Oil Food Resource, by Rosemary Extract
Antioxidants 2023, 12(4), 889; https://doi.org/10.3390/antiox12040889 - 06 Apr 2023
Viewed by 828
Abstract
Acer truncatum Bunge is a versatile, oil-producing, woody tree natively and widely distributed in northern China. In 2011, The People’s Republic of China’s Ministry of Health certified Acer truncatum seed oil (Aoil) as a new food resource. Unsaturated fatty acids account for up [...] Read more.
Acer truncatum Bunge is a versatile, oil-producing, woody tree natively and widely distributed in northern China. In 2011, The People’s Republic of China’s Ministry of Health certified Acer truncatum seed oil (Aoil) as a new food resource. Unsaturated fatty acids account for up to 92% of the entire Aoil. When Aoil is processed or stored, it can easily oxidize. In this study, the effects of rosemary (Rosmarinus officinalis L.) extract on the oxidation stability of Aoil were analysed from multiple angles. The results of radical scavenging ability, malondialdehyde, and free fatty acid reveal that rosemary crude extract (RCE), rosmarinic acid (RA), and carnosic acid (CA) can significantly inhibit the oxidation of Aoil, and CA has the best oxidative stability for Aoil among the tested components of the crude rosemary. The delayed oxidation ability of CA for Aoil was slightly weaker than that of tert-butylhydroquinone (TBHQ), but stronger than that of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol (α-T), which was confirmed by microstructures, kinematic viscosity, Aoil weight change, and functional group. Additionally, CA-enriched Aoil had the smallest content of volatile lipid oxidation products. Moreover, lecithin-CA particles were added to enhance the oxidative stability of Aoil. These findings show that CA is a potent antioxidant, capable of successfully preventing Aoil oxidation. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Antioxidant Properties of Thymoquinone, Thymohydroquinone and Black Cumin (Nigella sativa L.) Seed Oil: Scavenging of Superoxide Radical Studied Using Cyclic Voltammetry, DFT and Single Crystal X-ray Diffraction
Antioxidants 2023, 12(3), 607; https://doi.org/10.3390/antiox12030607 - 01 Mar 2023
Viewed by 820
Abstract
Black cumin seeds and seed oil have long been used in traditional foods and medicine in South Asian, Middle Eastern and Mediterranean countries and are valuable flavor ingredients. An important ingredient of black cumin is the small molecule thymoquinone (TQ), which manifests low [...] Read more.
Black cumin seeds and seed oil have long been used in traditional foods and medicine in South Asian, Middle Eastern and Mediterranean countries and are valuable flavor ingredients. An important ingredient of black cumin is the small molecule thymoquinone (TQ), which manifests low toxicity and potential therapeutic activity against a wide number of diseases including diabetes, cancer and neurodegenerative disorders. In this study, the antioxidant activities of black seed oil, TQ and a related molecule found in black cumin, thymohydroquinone (THQ), were measured using a direct electrochemical method to experimentally evaluate their superoxide scavenging action. TQ and the black seed oil showed good superoxide scavenging ability, while THQ did not. Density Functional Theory (DFT) computational methods were applied to arrive at a chemical mechanism describing these results, and confirmed the experimental Rotating Ring Disk Electrode (RRDE) findings that superoxide oxidation to O2 by TQ is feasible, in contrast with THQ, which does not scavenge superoxide. Additionally, a thorough inquiry into the unusual cyclic voltammetry pattern exhibited by TQ was studied and was associated with formation of a 1:1 TQ-superoxide radical species, [TQ-O2]•. DFT calculations reveal this radical species to be involved in the π-π mechanism describing TQ reactivity with superoxide. The crystal structures of TQ and THQ were analyzed, and the experimental data reveal the presence of stacking intermolecular interactions that can be associated with formation of the radical species, [TQ-O2]•. All three of these methods were essential for us to arrive at a chemical mechanism that explains TQ antioxidant activity, that incorporates intermolecular features found in the crystal structure and which correlates with the measured superoxide scavenging activity. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Effect of Flavorization on Virgin Olive Oil Oxidation and Volatile Profile
Antioxidants 2023, 12(2), 242; https://doi.org/10.3390/antiox12020242 - 21 Jan 2023
Viewed by 765
Abstract
The volatile compounds of virgin olive oil (VOO) have an important role from a sensory point of view as they are responsible for the aroma of the oil. Once the oil is obtained, auto-oxidation is the main process contributing to its deterioration, modifying [...] Read more.
The volatile compounds of virgin olive oil (VOO) have an important role from a sensory point of view as they are responsible for the aroma of the oil. Once the oil is obtained, auto-oxidation is the main process contributing to its deterioration, modifying the volatiles profile and aroma. The addition of aromatic herbs to VOO is a traditional technique to change the flavor and to preserve the oil. The aim of this study was to evaluate the effect on the volatile profile and sensory properties of flavoring VOO with rosemary and basil herbs and its impact on the evolution of the oxidative process during a six-month shelf-life study at 15.7 ± 3.6 °C and exposed to 500 ± 100 lx of light for 12 h each day. The determination of quality parameters, volatiles concentrations and VOO sensory properties and their comparison with the flavored VOO samples showed that the addition of basil or rosemary herbs, in addition to retarding the oxidation of the oil, allowed the discrimination of the flavored samples due to the migration of compounds from herbs to the oil. The aroma of basil olive oil (BOO) samples was mainly due to β-pinene, ocimene and 1,8-cineol compounds while for rosemary olive oil (ROO) samples, their aroma was mainly due to the concentrations of camphene, β-myrcene, α-terpinolene, limonene and 1,8-cineol. From the antioxidant standpoint, the effect of the herbs was more noticeable from the third month onwards. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Effect of Encapsulation Material on Lipid Bioaccessibility and Oxidation during In Vitro Digestion of Black Seed Oil
Antioxidants 2023, 12(1), 191; https://doi.org/10.3390/antiox12010191 - 13 Jan 2023
Viewed by 830
Abstract
Different encapsulation materials might not only affect lipid hydrolysis but also lipid oxidation during in vitro digestion. Thus, this study aimed to investigate the effect of two commonly used shell materials, starch and gelatin, on the extent of lipolysis and bioaccessibility of the [...] Read more.
Different encapsulation materials might not only affect lipid hydrolysis but also lipid oxidation during in vitro digestion. Thus, this study aimed to investigate the effect of two commonly used shell materials, starch and gelatin, on the extent of lipolysis and bioaccessibility of the main and some minor lipid compounds, as well as on the oxidative status in encapsulated black seed oil (Nigella sativa) during in vitro digestion. The study was carried out using 1H nuclear magnetic resonance spectroscopy, liquid chromatography-mass spectrometry and high-performance liquid chromatography-UV. It was shown that starch increased the level of lipid hydrolysis in black seed oil during gastric in vitro digestion, while no differences were observed in the intestinal digestates between starch-encapsulated oil and gelatin-encapsulated oil. Similarly, the bioaccessibility of minor compounds (tocopherols, sterols and thymoquinone) was not influenced by the shell materials. However, regarding lipid oxidation, a 20- and 10-fold rise of free oxylipins was obtained in oils encapsulated by starch and gelatin, respectively, after intestinal in vitro digestion. This study evidenced that gelatin rather than starch should be used for the encapsulation of oils to minimize the digestion-induced formation of bioactive oxylipins. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Impact of Phenolic Acid Derivatives on the Oxidative Stability of β-Lactoglobulin-Stabilized Emulsions
Antioxidants 2023, 12(1), 182; https://doi.org/10.3390/antiox12010182 - 12 Jan 2023
Viewed by 762
Abstract
Proteins, such as β-lactoglobulin (β-Lg), are often used to stabilize oil–water-emulsions. By using an additional implementation of phenolic compounds (PC) that might interact with the proteins, the oxidative stability can be further improved. Whether PC have a certain pro-oxidant effect on oxidation processes, [...] Read more.
Proteins, such as β-lactoglobulin (β-Lg), are often used to stabilize oil–water-emulsions. By using an additional implementation of phenolic compounds (PC) that might interact with the proteins, the oxidative stability can be further improved. Whether PC have a certain pro-oxidant effect on oxidation processes, while interacting non-covalently (pH-6) or covalently (pH.9) with the interfacial protein-film, is not known. This study aimed to characterize the impact of phenolic acid derivatives (PCDs) on the antioxidant efficacy of the interfacial β-Lg-film, depending on their structural properties and pH-value. Electron paramagnetic resonance (EPR) analyses were performed to assess the radical scavenging in the aqueous and oil phases of the emulsion, and the complexation of transition metals: these are well known to act as pro-oxidants. Finally, in a model linseed oil emulsion, lipid oxidation products were analyzed over storage time in order to characterize the antioxidant efficacy of the interfacial protein-film. The results showed that, at pH.6, PCDs can scavenge hydrophilic radicals and partially scavenge hydrophobic radicals, as well as reduce transition metals. As expected, transition metals are complexed to only a slight degree, leading to an increased lipid oxidation through non-complexed reduced transition metals. At pH.9, there is a strong complexation between PCDs and the transition metals and, therefore, a decreased ability to reduce the transition metals; these do not promote lipid oxidation in the emulsion anymore. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Green Carbon Dots as Additives of Biopolymer Films for Preserving from Oxidation of Oil-Based Products
Antioxidants 2022, 11(11), 2193; https://doi.org/10.3390/antiox11112193 - 05 Nov 2022
Viewed by 1061
Abstract
The deterioration of oil-based products during processing, distribution and storage has a major negative impact on the industry from an economic point of view. The spoilage of oil is mainly due to its oxidation which can be triggered by various factors, such as [...] Read more.
The deterioration of oil-based products during processing, distribution and storage has a major negative impact on the industry from an economic point of view. The spoilage of oil is mainly due to its oxidation which can be triggered by various factors, such as UV light, heating or the presence of impurities that result in the formation of radical species. In this context, several packaging alternatives have recently been developed with the aim to protect and extend the shelf life of oil-based products. This work aimed to study the antioxidant properties of bio-polymer-based films (BPFs) obtained from high methoxylated pectin (HMP) and sodium caseinate (CAS) and enriched with different concentrations of green carbon dots (gCDs), 0.25%, 0.50 and 1% w/w, obtained from apple pomace (APCDs) and rosemary powder (RCDs). The resulting films (gCDs-BPFs) have shown that the presence of gCDs not only modified the surface roughness of the films, but also positively affected their antioxidant properties. The addition of gCDs enhanced the radical inhibiting capacity of the raw BPFs by 42 and 62% for the films containing 1% RCDs and 1% APCDs, respectively. As a proof of the concept, two oil samples (edible and cosmetic) were treated with the obtained antioxidant films, and the results demonstrated that in both types of samples the oxidation process was minimized during the five days of the experiment. These results are promising and suggest that the antioxidant bio-polymer-based films could be excellent candidates for further production of active packaging. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Kinetic Analysis of High-Temperature Sunflower Oil Peroxidation Inhibited by the Major Families of Phenolic Antioxidants Unveils the Extraordinary Activity of 1,4-Hydroquinones
Antioxidants 2022, 11(11), 2142; https://doi.org/10.3390/antiox11112142 - 29 Oct 2022
Cited by 2 | Viewed by 838
Abstract
Peroxidation of vegetable oils represents a major problem for the food and biodiesel industries, and it is greatly accelerated by oil degree of unsaturation and by temperature increase. Phenols represent the most common additives used to counteract oil peroxidation, however clear structure-activity relationships [...] Read more.
Peroxidation of vegetable oils represents a major problem for the food and biodiesel industries, and it is greatly accelerated by oil degree of unsaturation and by temperature increase. Phenols represent the most common additives used to counteract oil peroxidation, however clear structure-activity relationships at high temperatures are not available. We report, herein, a kinetic study of O2 consumption during spontaneous peroxidation of sunflower oil at 130 °C in the presence of 18 antioxidants belonging to the main families of natural and synthetic phenols, including α-tocopherol, alkylphenols (BHT, BHA), hydroquinones (TBHD), catechols (quercetin, catechin) and gallates. Results show that TBHQ provide the best protection in terms of induction period (IP) duration and O2 consumption rate. EPR spectroscopy demonstrated that the inhibition activity is negatively correlated to the stability of the phenoxyl radical of the antioxidant (A), suggesting that chain propagation with linoleate (RH) moieties A + RH → AH + R decreases the efficacy of those antioxidants forming persistent A radicals. These results provide important information to optimize the antioxidant activity of phenols and of novel phenol-based materials. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Red Raspberry Seed Oil Low Energy Nanoemulsions: Influence of Surfactants, Antioxidants, and Temperature on Oxidative Stability
Antioxidants 2022, 11(10), 1898; https://doi.org/10.3390/antiox11101898 - 25 Sep 2022
Viewed by 1180
Abstract
The aim of this study was to assess and improve the oxidative stability of red raspberry seed oil–RO, a potential topical ingredient derived from food industry by-products, on its own and when incorporated in low energy nanoemulsion (NE). The RO’s oxidative stability was [...] Read more.
The aim of this study was to assess and improve the oxidative stability of red raspberry seed oil–RO, a potential topical ingredient derived from food industry by-products, on its own and when incorporated in low energy nanoemulsion (NE). The RO’s oxidative stability was assessed at 5, 25, and 40 °C during one month of storage and expressed in: peroxide value, p-anisidine, and thiobarbituric reactive substances—TBARS value, while for NEs, lipid hydroperoxides and TBARS values were monitored. Both synthetic (butylated hydroxytoluene—BHT and ethylenediaminetetraacetic acid—EDTA), and natural (oregano essential oil—ORE and oak fruit extract—OAK) antioxidants were used. Pure RO and RO with BHT or ORE were stable at 5 °C and 25 °C, but at 40 °C BHT showed only moderate protection, while ORE was prooxidant. NEs prepared with new biodegradable polyglycerol esters-based surfactants, with droplet sizes of < 50 nm and narrow size distribution, showed improved physicochemical stability at room temperature, and especially at 40 °C, compared to NEs with polysorbate 80, which required the addition of antioxidants to preserve their stability. Natural antioxidants ORE and OAK were compatible with all NEs; therefore, their use is proposed as an effective alternative to synthetic antioxidants. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Article
Effects of the Chemical Composition on the Antioxidant and Sensory Characteristics and Oxidative Stability of Cold-Pressed Black Cumin Oils
Antioxidants 2022, 11(8), 1556; https://doi.org/10.3390/antiox11081556 - 11 Aug 2022
Cited by 1 | Viewed by 1249
Abstract
The antioxidant capacity (AC); amounts of tocopherols, sterols, and polycyclic aromatic hydrocarbons; oxidative parameters; fatty acid composition (FAC); and sensory quality of cold-pressed black cumin oils (CPBCOs) available on the Polish market were analyzed and compared. The AC levels of the CPBCO samples [...] Read more.
The antioxidant capacity (AC); amounts of tocopherols, sterols, and polycyclic aromatic hydrocarbons; oxidative parameters; fatty acid composition (FAC); and sensory quality of cold-pressed black cumin oils (CPBCOs) available on the Polish market were analyzed and compared. The AC levels of the CPBCO samples were determined using four assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH = 226.8–790.1 μmol TE/100 g), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS = 385.9–1465.0 μmol TE/100 g), cupric-reducing antioxidant capacity (CUPRAC = 975.3–19,823.3 μmol TE/100 g), and Folin–Ciocalteu assays (FC = 168.1–643.7 μmol TE/100 g). The FAC scores were typical for black cumin oil, except for the sample CPBCO4, which had a higher content of α-linolenic acid (C18:3 = 23.33%), pointing to possible oil adulteration. Additionally, the concentrations of total sterols (TSC = 372 mg/100 g) and tocopherols (TTC = 42.3 mg/100 g) in this sample were higher than those for other investigated oils (TSC = 159–222 mg/100 g, TTC = 1.9–10.4 mg/100 g respectively). The oxidative stability levels (IP = 8.21–37.34 h), peroxide values (PV = 21.36–123.77 meq O2/kg), acid values (AV = 6.40–22.02 mg KOH/kg), and the sums of four specific polycyclic aromatic hydrocarbons (∑4PAHs = 4.48–46.68 μg/kg) in the studied samples differed significantly (p < 0.05). A sensory lexicon including 12 attributes was developed and applied for the sensory evaluation of oils using a quantitative descriptive analysis (QDA). Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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Review

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Review
Partitioning of Antioxidants in Edible Oil–Water Binary Systems and in Oil-in-Water Emulsions
Antioxidants 2023, 12(4), 828; https://doi.org/10.3390/antiox12040828 - 28 Mar 2023
Viewed by 571
Abstract
In recent years, partitioning of antioxidants in oil–water two-phase systems has received great interest because of their potential in the downstream processing of biomolecules, their benefits in health, and because partition constant values between water and model organic solvents are closely related to [...] Read more.
In recent years, partitioning of antioxidants in oil–water two-phase systems has received great interest because of their potential in the downstream processing of biomolecules, their benefits in health, and because partition constant values between water and model organic solvents are closely related to important biological and pharmaceutical properties such as bioavailability, passive transport, membrane permeability, and metabolism. Partitioning is also of general interest in the oil industry. Edible oils such as olive oil contain a variety of bioactive components that, depending on their partition constants, end up in an aqueous phase when extracted from olive fruits. Frequently, waste waters are subsequently discarded, but their recovery would allow for obtaining extracts with antioxidant and/or biological activities, adding commercial value to the wastes and, at the same time, would allow for minimizing environmental risks. Thus, given the importance of partitioning antioxidants, in this manuscript, we review the background theory necessary to derive the relevant equations necessary to describe, quantitatively, the partitioning of antioxidants (and, in general, other drugs) and the common methods for determining their partition constants in both binary (PWOIL) and multiphasic systems composed with edible oils. We also include some discussion on the usefulness (or not) of extrapolating the widely employed octanol–water partition constant (PWOCT) values to predict PWOIL values as well as on the effects of acidity and temperature on their distributions. Finally, there is a brief section discussing the importance of partitioning in lipidic oil-in-water emulsions, where two partition constants, that between the oil-interfacial, POI, and that between aqueous-interfacial, PwI, regions, which are needed to describe the partitioning of antioxidants, and whose values cannot be predicted from the PWOIL or the PWOCT ones. Full article
(This article belongs to the Special Issue Antioxidants and Oxidative Stability in Fats and Oils)
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