Recent advances in understanding the interfacial activity of antioxidants in association colloids in bulk oil

The chemical stability of edible oils rich in polyunsaturated fatty acids (PUFAs) is a major challenge within the food and supplement industries, as lipid oxidation reduces oil quality and safety. Despite appearing homogeneous to the human eye, bulk oils are actually multiphase heterogeneous systems at the nanoscale level. Association colloids, such as reverse micelles, are spontaneously formed within bulk oils due to the self-assembly of amphiphilic molecules that are present, like phospholipids, free fatty acids, and/or surfactants. In bulk oil, lipid oxidation often occurs at the oil-water interface of these association colloids because this is where different reactants accumulate, such as PUFAs, hydroperoxides, transition metals, and antioxidants. Consequently, the efficiency of antioxidants in bulk oils is governed by their chemical reactivity, but also by their ability to be located close to the site of oxidation. This review describes the impact of minor constituents in bulk oils on the nature of the association colloids formed. And then the formation of mixed reverse micelles (LOOH, (co)surfactants, or antioxidations) during the peroxidation of bulk oils, as well as changes in their composition and structure over time are also discussed. The critical importance of selecting appropriate antioxidants and surfactants for the changes of interface and colloid, as well as the inhibition of lipid oxidation is emphasized. The knowledge presented in this review article may facilitate the design of bulk oil products with improved resistance to oxidation, thereby reducing food waste and improving food quality and safety.

Fish Oil Supplementation as an Omega-3 Fatty Acid Source during Gestation: Effects on the Performance of Awassi Ewes and Their Offspring

The primary aim of this research was to assess the impact of supplementing fish oil into the diet of pregnant Awassi ewes on various aspects of the dam's productive performance, offspring birth weight, colostrum yield and quality, milk production and composition, postpartum offspring performance, and the composition of fatty acids in milk. In this study, two different fat sources, namely palm oil (PO) and fish oil (FO), were utilized, with both being included at a rate of 2.4% of dietary dry matter (DM) during the initial 65 days of gestation (early gestation stage), and then at 2.1% DM from day 65 of gestation until lambing (late gestation stage). The study subjects were Awassi ewes with a body weight (BW) averaging 57 ± 1.5 kg and an age of 3.5 ± 1.2 years. These ewes were randomly assigned to one of four dietary treatments: (i) a diet containing only palm oil from day 0 to day 150 of pregnancy (PO, n = 15); (ii) a diet containing palm oil from day 0 to day 65 of pregnancy, followed by a diet containing fish oil from day 66 to day 150 of pregnancy (POFO, n = 16); (iii) a diet containing fish oil from day 0 to day 65 of pregnancy, followed by a diet containing palm oil from day 66 to day 150 of pregnancy (FOPO, n = 16); (iv) a diet containing only fish oil from day 0 to day 150 of pregnancy (FO, n = 16). Within each treatment, ewes were housed in three replicates, with each replicate further divided into three subgroups. The first two subgroups each contained eight ewes, while the third subgroup contained nine ewes. In addition, each treatment contained 10 primiparous and 15 multiparous ewes. The results indicated that the POFO treatment led to significant increases (p < 0.05) in birth weight, gestation length, and colostrum IgG concentration. However, it also resulted in a decrease (p < 0.001) in colostrum production and a reduction (p < 0.001) in the percentage of milk fat and milk protein. Furthermore, the milk from the POFO treatment exhibited higher levels of polyunsaturated fatty acids (PUFAs) (p < 0.001) compared to the PO and FOPO treatments, while the milk saturated fatty acids (SFA) were lower (p < 0.001). In conclusion, the addition of fish oil at a rate of 2.1% DM during the late pregnancy period showed promise for enhancing birth weight, colostrum IgG concentration, and the PUFA content in the milk.

Antioxidant Activities of Essential Oils and Their Major Components in Scavenging Free Radicals, Inhibiting Lipid Oxidation and Reducing Cellular Oxidative Stress

Antioxidant activities of five essential oils (cinnamon, thyme, clove, lavender and peppermint oils) and their major components (eugenol, thymol, linalool, and menthol) were evaluated on scavenging DPPH (2,2-diphenyl-1 picrylhydrazyl) free radicals, inhibiting polyunsaturated fatty acid oxidation in fish oil emulsion (FOE), and reducing oxidative stress in human red blood cells (RBC). The essential oils from cinnamon, thyme, clove and their main components, eugenol and thymol, exhibited the highest antioxidant activity in the FOE and RBC systems. It was found that the antioxidant activity of essential oils was positively correlated to the content of eugenol and thymol, while lavender and peppermint oils and their main components, linalool and menthol, had very low antioxidant activity. Compared with scavenging DPPH free radical activity, the antioxidant activity in FOE and RBC systems could better reflect the actual antioxidant potential of essential oil in preventing lipid oxidation and reducing oxidative stress in biological system.

Highly Valuable Fish Oil: Formation Process, Enrichment, Subsequent Utilization, and Storage of Eicosapentaenoic Acid Ethyl Esters

In recent years, as the demand for precision nutrition is continuously increasing, scientific studies have shown that high-purity eicosapentaenoic acid ethyl ester (EPA-EE) functions more efficiently than mixed omega-3 polyunsaturated fatty acid preparations in diseases such as hyperlipidemia, heart disease, major depression, and heart disease; therefore, the market demand for EPA-EE is growing by the day. In this paper, we attempt to review EPA-EE from a whole-manufacturing-chain perspective. First, the extraction, refining, and ethanolysis processes (fish oil and ethanol undergo transesterification) of EPA-EE are described, emphasizing the potential of green substitute technologies. Then, the method of EPA enrichment is thoroughly detailed, the pros and cons of different methods are compared, and current developments in monomer production techniques are addressed. Finally, a summary of current advanced strategies for dealing with the low oxidative stability and low bioavailability of EPA-EE is presented. In conclusion, understanding the entire production process of EPA-EE will enable us to govern each step from a macro perspective and accomplish the best use of EPA-EE in a more cost-effective and environmentally friendly way.

Effects of Tea Polyphenol and Its Combination with Other Antioxidants Added during the Extraction Process on Oxidative Stability of Antarctic Krill (Euphausia superba) Oil

Antarctic krill (Euphausia superba) oil contains high levels of marine omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In industrial production, krill oil is usually extracted from krill meals by using ethanol as a solvent. Water in the krill meal can be easily extracted by using ethanol as an extraction solvent. During the extraction process, the EPA and DHA are more easily oxidized and degraded when water exists in the ethanol extract of krill oil. Based on the analysis of peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), fatty acid composition, and lipid class composition, the present study indicated that the composite antioxidants (TP-TPP) consist of tea polyphenol (TP) and tea polyphenol palmitate (TPP) had an excellent antioxidant effect. By contrast, adding TP-TPP into ethanol solvent during the extraction process is more effective than adding TP-TPP into krill oil after the extraction process.

Free Radical Chain Reactions and Polyunsaturated Fatty Acids in Brain Lipids

Polyunsaturated fatty acyl chains (PUFAs) concentrate in the brain and give rise to numerous oxidative chemical degradation products. It is widely assumed that these products are the result of free radical chain reactions, and reactions of this type have been demonstrated in preparations where a single PUFA substrate species predominates. However, it is unclear whether such reactions can occur in the biologically complex milieu of lipid membranes where PUFA substrates are a minority species, and where diverse free radical scavengers or other quenching mechanisms are present. It is of particular interest to know whether they occur in brain, where PUFAs are concentrated and where PUFA oxidation products have been implicated in the pathogenesis of neurodegenerative disorders. To ascertain whether free radical chain reactions can occur in a complex brain lipid mixture, mouse brain lipids were extracted, formed into vesicles, and treated with a fixed number of hydroxyl radicals under conditions wherein the concentrations and types of PUFA-containing phospholipids were varied. Specific phospholipid species in the mixture were assayed by tandem mass spectrometry to quantify the oxidative losses of endogenous PUFA-containing phospholipids. Results reveal crosstalk between the oxidative degradation of ω3 and ω6 PUFAs that can only be explained by the occurrence of free radical chain reactions. These results demonstrate that PUFAs in a complex brain lipid mixture can participate in free radical chain reactions wherein the extent of oxidative degradation is not limited by the number of reactive oxygen species available to initiate such reactions. These reactions may help explain otherwise puzzling in vivo interactions between ω3 and ω6 PUFAs in mouse brain.

Bioconversion and performance of Black Soldier Fly (Hermetia illucens) in the recovery of nutrients from expired fish feeds

In modern aquaculture systems, feed is the main source of the waste being produced, including expired aquafeeds. There is a link between the expiration date of aquafeeds enriched with fish oil for marine fish and the observation of several physical and microbiological changes. Among these, lipid oxidation is worth highlighting, as this process is responsible for the loss of palatability of aquafeeds, which can lead to feeding rejection by the species being farmed. In this study, we used an expired fish aquafeed, which otherwise would be discarded as waste, as a substrate to feed Black Soldier Fly (BSF) larvae. Different replacement levels of expired aquafeed were used which unravelled the amount of n-3 fatty acids added to larval tissues of BSF larvae after 2, 7, and 10 days of feeding. Our results also showed that shorter trials and higher diet replacement levels induced a deleterious effect on final larval weight. Furthermore, amino acid and fatty acid larval contents were shaped by the supplied diet, with results supporting the inclusion of BSF meal in aquafeeds, due to the levels of lysine (5.6-8.9%), methionine (1.9-3.2%), and omega-3 fatty acids (14.5%) recorded. These results demonstrate that the re-introduction of an expired resource aiming to diversify the source of aquafeeds raw materials can be safely achieved through BSF biotransformation. Overall, BSF larvae can successfully recover important nutrients for aquafeeds targeting marine species and foster the production of value-added insects under a circular bioeconomy framework.

The Effect of Combined Superheated Steam Roasting and Smoking on the Quality Characteristic of Alaska Pollack (Gadus chalcogrammus) Roe

Alaska pollack roe (APR) is a protein source that is usually salted and fermented, containing a high salt content. Using a combination of superheated steam roasting and smoking, we developed a new low-salt ready-to-eat APR variant, whose quality characteristics we analyzed. The optimal conditions for roasting (216 °C for 4 min) and smoking (64 °C for 14 min) were obtained from sensorial attributes using response surface methodology. Under the optimal conditions, smoke-roasted APR had an overall acceptance (OA) score of 8.89. The combination of roasting and smoking significantly increased volatile basic nitrogen (VBN, 18.6%) and decreased the total bacterial count (TBC, 38.6%), while thiobarbituric acid reactive substances (TBARS) were not affected. Smoke-roasting APR also increased its nutritional content to 30% protein with 44% essential amino acids, and more than 40% DHA and EPA in 4.3% fat. During 30 days of storage, the OA, VBN, TBARS, and TBC values significantly changed with time and storage temperature (p < 0.05). The shelf life of the product was estimated to be 24 d. In conclusion, the combination of roasting and smoking APR could improve product quality and may be an alternative to diversify processed APR.

Effects of Vacuum Frying on the Preparation of Ready-to-Heat Batter-Fried and Sauced Chub Mackerel (Scomber japonicus)

Chub mackerel (CM) is a commercial fish in Korea, owing to its availability and nutritional values. This study aimed to develop a ready-to-heat (RTH) Korean preparation of CM, known as Godeungo gangjeong. We utilized vacuum frying technology to fry the CM and evaluated its quality. Conventional frying with a deep fryer was performed in parallel to assess the superiority of the vacuum fryer. We optimized the frying conditions of vacuum frying (VBF) and deep frying (DBF) using response surface methodology. At optimum conditions of 95 °C for 7 min 42 s, VBF produced better sensory, chemical, and microbial properties than DBF at 190 °C for 5 min 30 s. The nutritional values, including amino acid and fatty acid contents, were investigated and found to be higher in VBF than in DBF. Sensory properties also showed better scores on VBF than DBF, especially in appearance, aroma, taste, and overall acceptability. The VBF produced lower volatile basic nitrogen (VBN), thiobarbituric acid reactive substances (TBARS), and total bacterial count (TBC) than DBF. The findings confirmed that vacuum frying is a better option to produce RTH Godeungo gangjeong, since it provides less oxidation and maintains the product quality. Using the Arrhenius approach, the product was concluded to preserve both quality and safety for 9 months of storage at −18 °C.

Chitosan-Based Anti-Oxidation Delivery Nano-Platform: Applications in the Encapsulation of DHA-Enriched Fish Oil

Refined cobia liver oil is a nutritional supplement (CBLO) that is rich in polyunsaturated fatty acids (PUFAs), such as DHA and EPA; however, PUFAs are prone to oxidation. In this study, the fabrication of chitosan-TPP-encapsulated CBLO nanoparticles (CS@CBLO NPs) was achieved by a two-step method, including emulsification and the ionic gelation of chitosan with sodium tripolyphosphate (TPP). The obtained nanoparticles were inspected by dynamic light scattering (DLS) and showed a positively charged surface with a z-average diameter of between 174 and 456 nm. Thermogravimetric analysis (TGA) results showed the three-stage weight loss trends contributing to the water evaporation, chitosan decomposition, and CBLO decomposition. The loading capacity (LC) and encapsulation efficiency (EE) of the CBLO loading in CS@CBLO NPs were 17.77-33.43% and 25.93-50.27%, respectively. The successful encapsulation of CBLO in CS@CBLO NPs was also confirmed by the Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The oxidative stability of CBLO and CS@CBLO NPs was monitored by FTIR. As compared to CBLO, CS@CBLO NPs showed less oxidation with a lower generation of hydroperoxides and secondary oxidation products after four weeks of storage. CS@CBLO NPs are composed of two ingredients that are beneficial for health, chitosan and fish oil in a nano powdered fish oil form, with an excellent oxidative stability that will enhance its usage in the functional food and pharmaceutical industries.

Addition of Olive Leaf Extract to a Mixture of Algae and Extra Virgin Olive Oils Decreases Fatty Acid Oxidation and Synergically Attenuates Age-Induced Hypertension, Sarcopenia and Insulin Resistance in Rats

Olive-derived products, such as virgin olive oil (EVOO) and/or olive leaf extracts (OLE), exert anti-inflammatory, insulin-sensitizing and antihypertensive properties and may be useful for stabilizing omega 3 fatty acids (n-3 PUFA) due to their high content in antioxidant compounds. In this study, the addition of OLE 4:0.15 (w/w) to a mixture of algae oil (AO) rich in n-3 PUFA and EVOO (25:75, w/w) prevents peroxides formation after 12 months of storage at 30 °C. Furthermore, the treatment with the oil mixture (2.5 mL/Kg) and OLE (100 mg/Kg) to 24 month old Wistar rats for 21 days improved the lipid profile, increased the HOMA-IR and decreased the serum levels of miRNAs 21 and 146a. Treatment with this new nutraceutical also prevented age-induced insulin resistance in the liver, gastrocnemius and visceral adipose tissue by decreasing the mRNA levels of inflammatory and oxidative stress markers. Oil mixture + OLE also attenuated the age-induced alterations in vascular function and prevented muscle loss by decreasing the expression of sarcopenia-related markers. In conclusion, treatment with a new nutraceutical based on a mixture of EVOO, AO and OLE is a useful strategy for improving the stability of n-3 PUFA in the final product and to attenuate the cardiometabolic and muscular disorders associated with aging.

Effect of unsaturated fatty acids on glycation product formation pathways

Glycation and lipid oxidation in high-nutrient foods are closely related and exhibit complex interactions. To evaluate the effect of unsaturated fatty acids (UFAs) on glycation pathways, glycation products in glucose-lysine-UFA models were detected by ultra performance liquid chromatography-tandem mass spectrometry and electron spin resonance spectroscopy, together with multivariate data analysis. Results indicated that UFAs inhibited glucose oxidation by decreasing the contents of carbonyl compounds about 73.85-86.19%. UFAs promoted the formation of glycation products mainly via production of active radical. In three models, linoleic acid (LA) exhibits stronger glycation activity than oleic acid and eicosapentaenoic acid. LA significantly promoted radical formation, as well as the formation and degradation of fructosyllysine (FL), the signal intensity of active radical increased 647.45% and FL increased 78.73%. The comparison of E(k₃), E(k₇) and variable importance in projection values of orthogonal projections to latent structures discriminant analysis in three models also proved these conclusions. By studying the characteristics of LA on glycation in three UFA, we hypothesized that unsaturation is not the key factor in evaluating their effects on glycation, the radical activity, UFA solubility, spatial structure and interaction should be considered as potentially important factors.

In Vivo Digestion of Egg Products Enriched with DHA: Effect of the Food Matrix on DHA Bioavailability

The aim of the present study was to determine to what extent the food matrix could affect the release of docosahexaenoic acid (DHA) during digestion and its incorporation into systemic circulation. In this aim, three DHA-enriched egg products having the same composition but different structure were developed: omelet, hard-boiled egg, and mousse. Then, nine pigs fitted with T-shape cannulas at duodenal level and a jugular venous catheter were fed with the DHA-enriched egg products, and duodenal effluents and plasma were collected throughout the postprandial period. Results highlighted an undeniable effect of the food matrix on digestion parameters and DHA bioavailability. The transit of DHA and protein through the duodenum was faster after the ingestion of the mousse than after the ingestion of the omelet and hard-boiled egg. While most of the DHA and protein ingested under the form of mousse had already passed through the duodenum 4.5 h after its ingestion, significantly higher quantities were still present in the case of the omelet and hard-boiled egg. In terms of bioavailability, the omelet was the most efficient vector for delivering DHA into systemic circulation. It supplied 56% and 120% more DHA than the hard-boiled egg and the mousse, respectively.

Chemical Compositional Changes in Over-Oxidized Fish Oils

A recent study has reported that the administration during gestation of a highly rancid hoki liver oil, obtained by oxidation through sustained exposure to oxygen gas and incident light for 30 days, causes newborn mortality in rats. This effect was attributed to lipid hydroperoxides formed in the omega-3 long-chain polyunsaturated fatty acid-rich oil, while other chemical changes in the damaged oil were overlooked. In the present study, the oxidation condition employed to damage the hoki liver oil was replicated, and the extreme rancidity was confirmed. A detailed analysis of temporal chemical changes resulting from the sustained oxidative challenge involved measures of eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) omega-3 oil oxidative quality (peroxide value, para-anisidine value, total oxidation number, acid value, oligomers, antioxidant content, and induction time) as well as changes in fatty acid content, volatiles, isoprostanoids, and oxysterols. The chemical description was extended to refined anchovy oil, which is a more representative ingredient oil used in omega-3 finished products. The present study also analyzed the effects of a different oxidation method involving thermal exposure in the dark in contact with air, which is an oxidation condition that is more relevant to retail products. The two oils had different susceptibility to the oxidation conditions, resulting in distinct chemical oxidation signatures that were determined primarily by antioxidant protection as well as specific methodological aspects of the applied oxidative conditions. Unique isoprostanoids and oxysterols were formed in the over-oxidized fish oils, which are discussed in light of their potential biological activities.

A Mixture of Algae and Extra Virgin Olive Oils Attenuates the Cardiometabolic Alterations Associated with Aging in Male Wistar Rats

Aging is one of the major risk factors for suffering cardiovascular and metabolic diseases. Due to the increase in life expectancy, there is a strong interest in the search for anti-aging strategies to treat and prevent these aging-induced disorders. Both omega 3 polyunsaturated fatty acids (ω-3 PUFA) and extra virgin olive oil (EVOO) exert numerous metabolic and cardiovascular benefits in the elderly. In addition, EVOO constitutes an interesting ingredient to stabilize ω-3 PUFA and decrease their oxidation process due to its high content in antioxidant compounds. ω-3 PUFA are commonly obtained from fish. However, more ecological and sustainable sources, such as algae oil (AO) can also be used. In this study, we aimed to study the possible beneficial effect of an oil mixture composed by EVOO (75%) and AO (25%) rich in ω-3 PUFA (35% docosahexaenoic acid (DHA) and 20% eicosapentaenoic acid (EPA)) on the cardiometabolic alterations associated with aging. For this purpose; young (three months old) and old (24 months old) male Wistar rats were treated with vehicle or with the oil mixture (2.5 mL/kg) for 21 days. Treatment with the oil mixture prevented the aging-induced increase in the serum levels of saturated fatty acids (SFA) and the aging-induced decrease in the serum concentrations of mono-unsaturated fatty acids (MUFA). Old treated rats showed increased serum concentrations of EPA and DHA and decreased HOMA-IR index and circulating levels of total cholesterol, insulin and IL-6. Treatment with the oil mixture increased the mRNA levels of antioxidant and insulin sensitivity-related enzymes, as well as reduced the gene expression of pro-inflammatory markers in the liver and in cardiac and aortic tissues. In addition, the treatment also prevented the aging-induced endothelial dysfunction and vascular insulin resistance through activation of the PI3K/Akt pathway. Moreover, aortic rings from old rats treated with the oil mixture showed a decreased response to the vasoconstrictor AngII. In conclusion, treatment with a mixture of EVOO and AO improves the lipid profile, insulin sensitivity and vascular function in aged rats and decreases aging-induced inflammation and oxidative stress in the liver, and in the cardiovascular system. Thus, it could be an interesting strategy to deal with cardiometabolic alterations associated with aging.

Single and Repeated Dose 28-Day and 13-Week Toxicity Studies of Oil Prepared from the Internal Organs of the Japanese Giant Scallop (Patinopecten yessoensis) in Mice

Internal organs of discarded scallops are rich in omega-3 polyunsaturated fatty acids, but it is not used as a food ingredient due to the presence of toxic substances. Recently, our research team prepared high-quality scallop oil (SCO) from the internal organs of the Japanese giant scallop (Patinopecten yessoensis), in which cadmium and diarrhetic shellfish toxin are below regulated levels. In this study, SCO was prepared from the internal organs of scallops obtained from Mutsu and Uchiura bays in Japan, and was referred to as SCO-M (scallop oil from Mutsu bay) and SCO-U (scallop oil from Uchiura bay), respectively. Acute and subacute toxicity studies were performed to assess the safety of the prepared SCO. In acute toxicity study, mice were orally administered SCO-M and SCO-U at a single dose of 5,000 mg/kg body weight. In a 28-day repeated oral dose toxicity study, the mice were fed diets containing 1% and 5% SCO-M and SCO-U; and in a 13-week repeated oral dose toxicity study, the mice were fed 5% SCO-M and SCO-U. There were no toxicologically significant changes in clinical signs, hematology, blood chemistry, and organ weights at any dose during the experiment. Therefore, it was concluded that SCO-M and SCO-U are safe for use as food ingredients under the experimental conditions of this study.