The use of natural antioxidants to combat lipid oxidation in O/W emulsions

Microencapsulation of peanut skin polyphenols for shelf life improvement of sunflower seeds

Derived from industrial processing waste, peanut skins contain polyphenols that delay oxidative food spoilage. However, these compounds are susceptible to light, heat, and oxygen exposure. Microencapsulation provides a solution by offering protection from these factors. The aim of this study was to evaluate the protective effect of peanut skin extract microcapsules on the chemical, microbiological, and sensory property and shelf life of sunflower seeds during storage. Five roasted sunflower seed samples were prepared: control (S-C); added with butylhydroxytoluene (S-BHT); coated with carboxymethyl cellulose (S-CMC); coated with CMC and the addition of peanut skin crude extract (S-CMC-CE); coated with CMC and the addition of microcapsules (S-CMC-M20). Sensory acceptability was determined using hedonic testing. Chemical (peroxide value, conjugated dienes, hexanal and nonanal content, and fatty acid profile), microbiological, and descriptive analyses were carried out on samples stored for 45 days at room temperature. Shelf life was calculated using a simple linear regression. All samples were microbiologically fit for human consumption and accepted by consumer panelists, scoring above five points on the nine-point hedonic scale. S-CMC-M20 exhibited the lowest peroxide value (6.59 meqO2/kg) and hexanal content (0.4 µg/g) at the end of the storage. Estimated shelf life showed that S-MC-M20 (76.3 days) extended its duration nearly ninefold compared to S-C (8.3 days) and doubled that of S-CMC-CE (37.5 days). This indicates a superior efficacy of microencapsulated extract compared to its unencapsulated form, presenting a promising natural strategy for improving the shelf life of analogous food items. PRACTICAL APPLICATION: Incorporating peanut skin extract microcapsules in coating sunflower seeds presents a promising strategy to extend the shelf life of lipid-rich foods, capitalizing on the antioxidant properties of polyphenols. This innovative approach not only enhances nutritional quality but also addresses sustainability concerns by repurposing agro-industrial byproducts, such as peanut skins. By meeting consumer demand for functional foods with added health benefits, this technique offers potential opportunities for the development of novel, value-added food products while contributing to circular economy principles and waste management efforts.

Influence of Cuttlefish-Ink Extract on Canned Golden Seabream (Sparus aurata) Quality

Four different concentrations of an aqueous extract of cuttlefish (Sepia spp.) ink (CI) were introduced, respectively, into the packing medium employed during golden seabream (Sparus aurata) canning. The quality parameters of the resulting canned fish were determined and compared to the initial fish and the control canned muscle. An important effect of the CI concentration introduced in the packing medium was proved. The presence in the packing medium of a relatively low CI concentration (CI-2 batch) led to a lower (p < 0.05) lipid oxidation development (fluorescent compound formation), lower (p < 0.05) changes of colour parameters (L* and a* values), and lower (p < 0.05) trimethylamine values in canned fish when compared to control canned samples. Additionally, the two lowest CI concentrations tested led to higher average values of C22:6ω3, ω3/ω6 ratios, and polyene index. On the contrary, the use of the most concentrated CI extract (CI-4 condition) led to a prooxidant effect (higher fluorescence ratio value). In agreement with environmental sustainability and circular economy requirements, the study can be considered the first approach to a novel and valuable use of the current marine byproduct for the quality enhancement of canned fish. On-coming research focused on the optimisation of the CI-extract concentration is envisaged.

Enhanced thermophilic dark fermentation of hydrogen production from food waste by Fe-modified biochar

The industrialization of hydrogen production through dark fermentation of food waste faces challenges, such as low yields and unpredictable fermentation processes. Biochar has emerged as a promising green additive to enhance hydrogen production in dark fermentation. Our study demonstrated that the introduction of Fe-modified biochar (Fe-L600) significantly boosted hydrogen production during thermophilic dark fermentation of food waste. The addition of Fe-L600 led to a remarkable 31.19% increase in hydrogen yield and shortened the time needed for achieving stabilization of hydrogen production from 18 h to 12 h. The metabolite analysis revealed an enhancement in the butyric acid pathway as the molar ratio of acetic acid to butyric acid decreased from 3.09 to 2.69 but hydrogen yield increased from 57.12 ± 1.48 to 76.78 ± 2.77 mL/g, indicating Fe-L600 improved hydrogen yield by regulating crucial metabolic pathways of hydrogen production. The addition of Fe-L600 also promoted the release of Fe2+ and Fe3+ and increased the concentrations of Fe2+ and Fe3+ in the fermentation system, which might promote the activity of hydrogenase and ferredoxin. Microbial community analysis indicated a substantial increase in the relative abundance of Thermoanaerobacterium after thermophilic dark fermentation. The relative abundances of microorganisms responsible for hydrolysis and acidogenesis were also observed to be improved in the system with Fe-L600 addition. This research provides a feasible strategy for improving hydrogen production of food waste and deepens the understanding of the mechanisms of biochar.

Glyoxal in Foods: Formation, Metabolism, Health Hazards, and Its Control Strategies

Glyoxal is a highly reactive aldehyde widely present in common diet and environment and inevitably generated through various metabolic pathways in vivo. Glyoxal is easily produced in diets high in carbohydrates and fats via the Maillard reaction, carbohydrate autoxidation, and lipid peroxidation, etc. This leads to dietary intake being a major source of exogenous exposure. Exposure to glyoxal has been positively associated with a number of metabolic diseases, such as diabetes mellitus, atherosclerosis, and Alzheimer's disease. It has been demonstrated that polyphenols, probiotics, hydrocolloids, and amino acids can reduce the content of glyoxal in foods via different mechanisms, thus reducing the risk of exogenous exposure to glyoxal and alleviating carbonyl stresses in the human body. This review discussed the formation and metabolism of glyoxal, its health hazards, and the strategies to reduce such health hazards. Future investigation of glyoxal from different perspectives is also discussed.

Evaluation of the Emulsifying Property and Oxidative Stability of Myofibrillar Protein-Diacylglycerol Emulsions Containing Catechin Subjected to Different pH Values

Myofibrillar protein-diacylglycerol emulsions containing catechin (MP-DAG-C) possess outstanding emulsifying property and oxidative stability. However, the effect of pH on MP-DAG-C emulsions should be revealed to provide possibilities for their application in practical meat products. Therefore, MP-DAG-C emulsions at different pH values were used in this study, in which lard, unpurified glycerolytic lard (UGL), and purified glycerolytic lard (PGL) were used as the oil phases. The results indicated that the emulsifying property of the UGL- and PGL-based emulsions increased compared to those of the lard-based emulsions (p < 0.05). The emulsifying activity and stability indices, absolute value of ζ-potential, and rheological characteristics increased with the increase in pH values (p < 0.05), with the droplets were smallest and distributed most uniformly at a pH of 6.5 compared to the other acidic environment (p < 0.05). The thiobarbituric acid substance and carbonyl content increased (p < 0.05), while the total sulfydryl content decreased (p < 0.05) during storage. However, there was no statistical difference between the oxidative stability of the MP-DAG-C emulsions with different pH values (p > 0.05). The results implied that the emulsifying property of MP-DAG-C emulsions increased with an increase in pH values. The oxidative stability of the MP-DAG-C emulsions at high pH values was improved by catechin.

Arabic gum grafted with phenolic acid as a novel functional stabilizer for improving the oxidation stability of oil-in-water emulsion

Three kinds of phenolic acids: ferulic acid (FA), caffeic acid (CA), and gallic acid (GA) with different chemical structures were individually grafted onto Arabic gum (AG) via a laccase mediated method, and their roles in stabilizing o/w emulsions were evaluated. The total phenolic content in modified AG increased from 2.7 ± 0.2 to 18.7 ± 0.2, 19.8 ± 0.6, 22.4 ± 0.8 mg/g after 4 h of laccase catalysis, respectively. FTIR spectra of modified AGs exhibited additional phenolic characteristics, revealing the successful grafting of phenolic acids to AG structure. Compared with natural AG, modified AGs showed remarkably enhanced thermal stability, as well as antioxidant capacity in an order of gallic acid > caffeic acid > ferulic acid. The incorporation of phenolic acids into AG dramatically improved its emulsification performance. Herein, gallic acid-modified AG evinced up to 17.6 % and 12.6 % increments in emulsifying activity and emulsion stability relative to natural AG, respectively. Moreover, the oxidative stability of AG emulsions was pronouncedly meliorated by the introduced phenolic acids, especially gallic acid, as manifested by the suppressed production of primary and secondary oxidation products.

The effect of α-tocopherol incorporated into different carriers on the oxidative stability of oil in water (O/W) emulsions

The effect of the antioxidant activity of α-tocopherol incorporated into different carriers on the oxidative stability of oil in water emulsion was investigated. The antioxidant activity of free and encapsulated α-tocopherol was measured in a 2,2-diphenyl-1-picrylhydrazyl reaction. Apart from α-tocopherol micelles, the samples showed similar antioxidant activity. The number of primary oxidation products in the emulsion with tocopherol liposomes and niosomes was lower than in the emulsion with micelles. During storage, the lipid peroxides gradually increased, whereas in emulsion with no α-tocopherol carriers added they remained constant. The content of the conjugated dienes first increased, and after 14 days at the end of testing time it remained stable in both types of emulsions. Our results might suggest that α-tocopherol when encapsulated into carriers exhibits lower antioxidant activity. The results obtained could be due to the better solubility of α-tocopherol in lipid droplets and thus the lower availability for the interfacial region, which is thought to be the place of the most pronounced lipid oxidation.

Characteristics of a Lipid Hydrogel and Bigel as Matrices for Ascorbic Acid Stabilization

Ascorbic acid (AA) has many health benefits, including immune and cardiovascular deficiency protection, prenatal problems, and skin diseases. Unfortunately, AA is easily oxidized and has limited bioavailability. Thus, the development of formulations that stabilize and enhance the efficacy of AA is a challenge. In this study, 4% AA was encapsulated in two recently developed gels, a hydrogel and a bigel. The hydrogel was formed exclusively with lipids and water, and the bigel was a combination of the hydrogel with an oleogel formed with olive oil and beeswax. The effect of AA in gel microstructures was determined using X-ray scattering, rheology, and texture analysis. Additionally, the capacity of these materials to protect AA from degradation upon temperature and sunlight was studied. Results showed that the incorporation of AA into both materials did not affect their microstructure. Moreover, hydrogel-protected AA showed only 2% degradation after three months at 8 °C, while in aqueous solution, it degraded by 12%. Regarding sunlight, bigel showed a good shielding effect, exhibiting only 2% AA degradation after 22 h of exposure, whereas in aqueous solution, AA degraded by 10%. These results suggest that both proposed gels could be used in biomedical applications and the field of food.

Potential of Syzygnium polyanthum as Natural Food Preservative: A Review

Food preservation is one of the strategies taken to maintain the level of public health. Oxidation activity and microbial contamination are the primary causes of food spoilage. For health reasons, people prefer natural preservatives over synthetic ones. Syzygnium polyanthum is widely spread throughout Asia and is utilized as a spice by the community. S. polyanthum has been found to be rich in phenols, hydroquinones, tannins, and flavonoids, which are potential antioxidants and antimicrobial agents. Consequently, S. polyanthum presents a tremendous opportunity as a natural preservative. This paper reviews recent articles about S. polyanthum dating back to the year 2000. This review summarizes the findings of natural compounds presented in S. polyanthum and their functional properties as antioxidants, antimicrobial agents, and natural preservatives in various types of food.

Antioxidant Activities of Dihydromyricetin Derivatives with Different Acyl Donor Chain Lengths Synthetized by Lipozyme TL IM

Dihydromyricetin (DHM) is a phytochemical with multiple bioactivities. However, its poor liposolubility limits its application in the field. In this study, DHM was acylated with different fatty acid vinyl esters to improve its lipophilicity, and five DHM acylated derivatives with different carbon chain lengths (C2-DHM, C4-DHM, C6-DHM, C8-DHM, and C12-DHM) and different lipophilicity were synthesized. The relationship between the lipophilicity and antioxidant activities of DHM and its derivatives was evaluated with oil and emulsion models using chemical and cellular antioxidant activity (CAA) tests. The capacity of DHM derivatives to scavenge 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS+•) was similar to that of DHM, except for C12-DHM. The antioxidant activity of DHM derivatives was lower than that of DHM in sunflower oil, while C4-DHM exhibited better antioxidant capacity in oil-in-water emulsion. In CAA tests, C8-DHM (median effective dose (EC₅₀) 35.14 μmol/L) exhibited better antioxidant activity than that of DHM (EC₅₀: 226.26 μmol/L). The results showed that in different antioxidant models, DHM derivatives with different lipophilicity had various antioxidant activities, which has guiding significance for the use of DHM and its derivatives.

Integral Valorization of Grape Pomace for Antioxidant Pickering Emulsions

Full harnessing of grape pomace (GP) agricultural waste for the preparation of antioxidant Pickering emulsions is presented herein. Bacterial cellulose (BC) and polyphenolic extract (GPPE) were both prepared from GP. Rod-like BC nanocrystals up to 1.5 µm in length and 5-30 nm in width were obtained through enzymatic hydrolysis (EH). The GPPE obtained through ultrasound-assisted hydroalcoholic solvent extraction presented excellent antioxidant properties assessed using DPPH, ABTS and TPC assays. The BCNC-GPPE complex formation improved the colloidal stability of BCNC aqueous dispersions by decreasing the Z potential value up to -35 mV and prolonged the antioxidant half-life of GPPE up to 2.5 times. The antioxidant activity of the complex was demonstrated by the decrease in conjugate diene (CD) formation in olive oil-in-water emulsions, whereas the measured emulsification ratio (ER) and droplet mean size of hexadecane-in-water emulsions confirmed the physical stability improvement in all cases. The synergistic effect between nanocellulose and GPPE resulted in promising novel emulsions with prolonged physical and oxidative stability.

The Influence of Antioxidant Plant Extracts on the Oxidation of O/W Emulsions

The demand for natural cosmetics has steadily increased in recent years. However, challenges occur especially in quality preservation regarding oxidative spoilage of natural cosmetic products, as the use of synthetic preservatives and antioxidants is limited. Therefore, it is important to find nature-based ingredients to ensure shelf life in natural cosmetic formulations. As a result, potential is seen in the use of plant-based antioxidant extracts. The aim of this work was to determine the suitability of the method combination by measuring the antioxidant activity, oxygen concentration, and volatile oxidation products via gas chromatography (hexanal) for the characterization of the influence of some plant extracts on the oxidative stability of natural cosmetic emulsions. Plant extracts of Riesling (Vitis vinifera) pomace, apple (Malus domestica) pomace, coffee (Coffea arabica) grounds, cocoa (Theobroma cacao) husk, and coffee (Coffea arabica) powder extract were incorporated in stable O/W emulsion formulations, while an emulsion without extract functioned as blank. Afterwards, the emulsions were subjected to 3-month accelerated storage tests with and without light exposure. Their oxygen uptake was investigated, and headspace gas chromatography measurements were performed to detect the fatty acid oxidation products formed during oxidative processes in the samples. The results showed that all emulsion samples under light exposure had a higher oxygen uptake and an increase in the characteristic fatty acid oxidation products compared with those stored under light exclusion. However, differences in oxygen uptake under light exposure were observed depending on the plant extract. Therefore, for O/W emulsions, the daily oxygen consumption rate correlated exponentially with the antioxidant activity, and the hexanal concentration correlated linearly with the daily oxygen consumption rate.

Review on the Antioxidant Activity of Phenolics in o/w Emulsions along with the Impact of a Few Important Factors on Their Interfacial Behaviour

This review paper focuses on the antioxidant properties of phenolic compounds in oil in water (o/w) emulsion systems. The authors first provide an overview of the most recent studies on the activity of common, naturally occurring phenolic compounds against the oxidative deterioration of o/w emulsions. A screening of the latest literature was subsequently performed with the aim to elucidate how specific parameters (polarity, pH, emulsifiers, and synergistic action) affect the phenolic interfacial distribution, which in turn determines their antioxidant potential in food emulsion systems. An understanding of the interfacial activity of phenolic antioxidants could be of interest to food scientists working on the development of novel food products enriched with functional ingredients. It would also provide further insight to health scientists exploring the potentially beneficial properties of phenolic antioxidants against the oxidative damage of amphiphilic biological membranes (which link to serious pathologic conditions).

Antioxidant Capacity and Protective Effect of Cow Placenta Extract on D-Galactose-Induced Skin Aging in Mice

Placental extract has been used for skin care and delaying skin aging. Cow placenta is an abundant resource with a large mass, which has not been harnessed effectively. Cow placenta extract (CPE) has the functions of antioxidation, anti-inflammatory, promoting growth and development, and promoting hair growth. However, little is known about the effect of oral administration of cow placenta extract on skin conditions. Therefore, the present study aimed to investigate the antioxidant capacity of CPE in vitro and in vivo and its protective effect on d-galactose (D-gal) induced skin aging in mice. The results showed that CPE had strong free radical scavenging, reducing and metal chelating activities. CPE can increase the activity of catalase (CAT), glutathione peroxidase (GSH-Px), peroxidase (POD), superoxide dismutase (SOD), and the content of glutathione (GSH), decrease the content of malondialdehyde (MDA). Moreover, CPE can decrease the gene and protein expression of matrix metalloproteinase 1a (MMP-1a) and matrix metalloproteinase 3 (MMP-3) and increase the expression of transforming growth factor-β (TGF-β) and tissue inhibitor of metalloproteinase 1 (TIMP-1) of mouse skin. Histopathological analysis showed CPE reduced the collagen damage caused by D-gal, increased collagen synthesis and reduced its degradation to delay skin aging.

Probing the synergistic effects of rutin and rutin ester on the oxidative stability of sardine oil

Multicomponent antioxidant mixture is proved to be highly effective in imparting oxidative stability to the edible oil. It is believed that the high efficacy of those mixtures is due to the synergistic effect exhibited by two or more components. The current study aims to analyse the synergistic effect of a flavonoid and its corresponding ester in improving the oxidative stability of n-3 PUFA rich sardine oil. The oxidative stability of rutin, esterified rutin and their combinations at three different concentrations was studied in sardine oil stored at 37 ºC for 12 days in contact with air under darkness. The combination of rutin and rutin ester showed maximum reduction of 54.2% in oxidation at 100 mg/kg and 150 mg/kg. Perhaps this is the first report on the synergistic effect of a flavonoid and its lipophilized ester for improving the oxidative stability of n-3 PUFA rich oil.

Effects of antioxidant types on the stabilization and in vitro digestion behaviors of silver carp scale gelatin-stabilized fish oil-loaded emulsions

Lipid oxidation is a major challenge in the development and storage of lipid-containing food products. In this work, we extracted aquatic gelatin from silver carp scales and studied the effects of antioxidant types (water-soluble and lipid-soluble types) on the stabilization, lipid oxidation, and in vitro digestion behaviors of silver carp scale gelatin-stabilized fish oil-loaded emulsions. Vitamin C (VC), a water-soluble antioxidant, and vitamin E (VE), a lipid-soluble antioxidant, had no obvious effects on the appearance, droplet size distribution, and droplet stability of the emulsion. VC slowed the liquid-gel transition of the emulsions at room temperature. The emulsion creaming stability decreased with the increase of VC concentration, whereas it increased with the increase of VE concentration. Lipid oxidation hierarchy of emulsion groups at room temperature were VC<VE<control<pure oil. Free fatty acids were mainly released from the silver carp scale gelatin-stabilized emulsions in the simulated intestinal fluid. Moreover, compared with the control group, VC increased the free fatty acid release percentages, whereas VE decreased them. This work provided useful information for developing antioxidants in the field of food science and in value-added utilization research of aquatic by-products.

Phenolics in buckwheat hull extracts and their antioxidant activities on bulk oil and emulsions

Buckwheat hulls are discarded as waste, although they have more phenolic compounds than buckwheat groats. The antioxidant activities of buckwheat hull extracts prepared with water, 50% ethanol, and 100% ethanol were investigated in bulk oil, oil-in-water (O/W), and water-in-oil (W/O) emulsions. The relationship between the phenolic compositions of the extracts and their antioxidant activities in the three different lipid systems was also evaluated. Fifty percent ethanol extract had the highest total phenolic content (327 mg gallic acid equivalent [GAE]/g extract) followed by water and 100% ethanol extracts (211 and 163 mg GAE/g extract, respectively). The total oxidation rate (k) was not significantly different among the bulk oils added with the buckwheat hull extracts. However, in the O/W emulsion, the k was more reduced by the 50% and 100% ethanol extracts than by the water extract at the concentration of 100 µg GAE/g (2.9, 2.8, and 3.7 Totox/day, respectively). The k of the W/O emulsion was more reduced by the 100% ethanol extract than by the water and 50% ethanol extract at the concentration of 100 µg GAE/g (3.8, 4.7, and 4.5 Totox/day, respectively). Multivariate statistical analysis revealed that the contents of phenolic acids and their derivatives were the highest in the water extract among the extracts, while the contents of flavonoid glycosides and methylated polyphenols were the highest in the 50% and 100% ethanol extracts, respectively. The results suggest that flavonoid glycosides and methylated polyphenols could be potential candidates for retarding the oxidation of the emulsion system. PRACTICAL APPLICATION: Buckwheat hull extracts could retard lipid oxidation. Flavonoid glycosides and methylated polyphenols in buckwheat hull extracts may have an antioxidative effect on lipids. Thus, buckwheat hulls could be used as an antioxidant in lipid systems, as flavonoid glycosides and methylated polyphenols are properly extracted from buckwheat hulls.

Lipid oxidation and antioxidant delivery systems in muscle food

Lipid oxidation accelerates quality deterioration in muscle-based foods (fish, red meat, and poultry), resulting in off-odors/flavors, color problems, texture defects, and safety concerns. Adding antioxidants is one approach to control lipid oxidation, and several delivery strategies have been applied, such as supplementing antioxidants to the feed, direct mixing into minces, or, for whole muscle pieces; spraying, glazing, and injection. However, some issues linked to these technologies hinder their wide utilization, such as low effectiveness, noncompatibility with clean label, and off-flavor. These shortcomings have promoted the development of new antioxidant delivery technologies. In this review, the main focus is on the principles, characteristics, and implementation of five novel antioxidant delivery methods in different types of muscle food products. Their advantages and drawbacks are also summarized, plus comments about future trends in this area. Among novel routes to deliver antioxidants to muscle foods are, for whole tissues, recyclable dipping solutions; for minces, encapsulation; and, for both minces and whole tissues, cross-processing with nonmuscle antioxidant-containing raw materials as well as applications of edible films/coatings and active packaging. Advantages of these technologies comprise, for example, low price, the possibility to control the antioxidant release rate, overcoming strong aromas from natural antioxidants, and allowing antioxidant-containing raw materials from the food industry to be valorized, providing an opportunity for more circular food production.

Recent advances on food-grade water-in-oil emulsions: Instability mechanism, fabrication, characterization, application, and research trends

Owing to their promising application prospects, water-in-oil (W/O) emulsions have aroused continuous attention in recent years. However, long-term stability of W/O emulsions remains a particularly challenging problem in colloid science. With the increasing demand of consumers for natural, green, and healthy foods, the heavy reliance on chemically synthesized surfactants to achieve long-term stability has become the key technical defect restricting the application of W/O emulsions in food. To design and manufacture W/O emulsions with long-term stability and clean label, a comprehensive understanding of the fundamentals of the W/O emulsion system is required. This review aims to demystify the field of W/O emulsions and update its current research progress. We first provide a summary on the essential basic knowledge regarding the instability mechanisms, including physical and chemical instability in W/O emulsions. Then, the formulation of the W/O emulsion system is introduced, particularly focusing on the use of natural stabilizers. Besides, the characterization and application of W/O emulsions are also discussed. Finally, we propose promising research trends, including (1) developing W/O high internal phase emulsions (HIPEs) as fat mimetic and substitute, (2) promising formulation routine for long-term stable double emulsions, and (3) searching for novel plant-derived stabilizers of W/O emulsions.

A comprehensive review on polarity, partitioning, and interactions of phenolic antioxidants at oil-water interface of food emulsions

There has been a growing interest in developing effective strategies to inhibit lipid oxidation in emulsified food products by utilization of natural phenolic antioxidants owing to their growing popularity over the past decades. However, due to the complexity of emulsified systems, the inhibition mechanism of phenolic antioxidants against lipid oxidation is rather complicated and not yet fully understood. In order to highlight the importance of polarity of phenolic antioxidants in emulsified systems according to the polar paradox, this review covers the recent progress on chemical, enzymatic, and chemoenzymatic lipophilization techniques used to modify the polarity of antioxidants. The partitioning behavior of phenolic antioxidants at the oil-water interface, which can be influenced by the presence of synthetic surfactants and/or antioxidant emulsifiers (e.g., polysaccharides, proteins, and phospholipids), is discussed. In addition, the emerging phenolic antioxidants among phenolic acids, flavonoids, tocopherols, and stilbenes applied in food emulsions are elaborated. As well, the interactions of polar-nonpolar antioxidants are stressed as a promising strategy to induce synergistic interactions at oil-water interface for improved oxidative stability of emulsions.

Synergistic potential of nutraceuticals: mechanisms and prospects for futuristic medicine

Nutraceuticals are valued for their therapeutic effects and numerous health benefits. In recent years, several studies have demonstrated their superior performances when co-delivered; the concept of synergism has been established for various bioactives. Apart from improvements in the bioavailability of partnering compounds, this approach can protect the radical scavenging potential and biological effects of individual compounds. In this review, the intricate mechanisms that promote synergistic effects when bioactive compounds are co-delivered are detailed. Importantly, a range of potential medical applications that have been established through such synergistic effects is presented, emphasizing recent developments in this field. Also, a section has been devoted to highlighting perspectives on co-encapsulation at the nanoscale for improved synergistic benefits. While prospects for the treatment of chronic diseases are well-demonstrated, several challenges and safety concerns remain, and these have been discussed, providing recommendations for future research.

Potential development of non-synthetic food additives from orange processing by-products—a review

Citrus is the largest fruit crop worldwide. Meanwhile, oranges account for 60 per cent of the total, with their main application in juice production. During orange juice production, only about 50 per cent of the fresh orange weight is transformed into juice, with the remaining 50 per cent comprised of residue (peel, pulp, seeds, orange leaves and whole orange fruits that do not reach the quality requirements). With the resulting tons of orange by-products, there has been an initiative to research possible ways to reutilize and revalorize citrus waste. Orange pomace, the by-product from juicing process, is currently used to extract the essential oils for fragrance and flavor, and a majority of the waste is used as cattle feed; however, these applications do not account for all of the waste or capture all of its potential value. Meanwhile, these by-products are put into landfills at the owner’s expense, and contribute to global warming through carbon emissions. On the other hand, orange by-products still contain many useful nutraceutical components, such as dietary fiber and phytochemicals, which could be utilized for value-added ingredients and new product development. Some research approaches in this area include the production of organic fertilizers and biofuels, or the extraction of essential oils, pectins, and antioxidant compounds. There is little information in the literature and in the food industry in terms of utilizing the orange pomace directly or with some simple treatments. Orange pomace may be used for food product development as a ‘clean-label’, non-synthetic preservative, which rationalizes this review.

Comparison of antioxidant activities of selected phenolic compounds in O/W emulsions and bulk oil

Antioxidant activities of 1-o-galloylglycerol (GG), propyl gallate, rosmarinic acid (RA), tocopherols (TOC), and 1:1 combinations of GG/RA and GG/TOC were evaluated using in vitro assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS⁺), and ferric reducing antioxidant power (FRAP). Soybean oil stripped of TOC was utilized as bulk oil and as the oil phase in O/W emulsions for accelerated oxidation test with the selected phenolic compounds. Efficacies of antioxidants were evaluated by monitoring total oxidation (TOTOX) values and fatty acid profiles of oil and O/W samples during the accelerated oxidation. In bulk oil, GG outperformed other singular antioxidants, preventing 39.04% of oxidation for ω-3 fatty acids with a TOTOX value of 166.68. In emulsions, TOC outperformed other singular antioxidants, preventing 38.04% of oxidation with a TOTOX value of 196.72. Considering the polarities of the antioxidants and our testing systems, these results provide supporting evidence for the polar paradox theory.

Role of antioxidants on physicochemical properties and in vitro bioaccessibility of β-carotene loaded nanoemulsion under thermal and cold plasma discharge accelerated tests

The effects of water soluble antioxidant (ascorbic acid and EDTA), fat soluble antioxidant (α-tocopherol) and amphiphilic antioxidant (ascorbyl palmitate; AP) on the chemical physics and bioaccessibility of β-carotene loaded nanoemulsions (CNE) were investigated. During accelerated storage at 45 °C for 15 days, AP showed the highest protective actions against particle size growth, color fading, lipid oxidation, and β-carotene degradation in CNE (p < 0.05). CNE with AP was then subjected to treat with cold plasma (CP) induced reactive species system under various powers and contact times compared to control. AP was able to protect physical and oxidative stabilities of CNE as well as β-carotene integrity. The highest in vitro lipid digestibility, bioaccessibility and β-carotene stability were found in CNE with AP (p < 0.05). However, those properties were lowered after CP exposure. The results indicated that AP was a promising antioxidant in improving physical stability, oxidative stability, β-carotene retention, and β-carotene bioaccessibility of CNE.