Retarding Lipid Oxidation Research Articles

Ethanolic Cashew Leaf Extract Encapsulated in Tripolyphosphate–Chitosan Complexes: Characterization, Antimicrobial, and Antioxidant Activities

Ethanolic cashew leaf extract (ECL-E) is rich in phenolic compounds and shows remarkable antioxidative and antimicrobial activities. Encapsulation could stabilize ECL-E as the core. Tripolyphosphate (TPP)–chitosan (CS) nanoparticles were used to load ECL-E, and the resulting nanoparticles were characterized. The nanoparticles loaded with ECL-E at different levels showed differences in encapsulation efficiency (47.62–89.47%), mean particle diameters (47.30–314.60 nm), positive zeta potentials (40.37–44.24 mV), and polydispersity index values (0.20–0.56). According to scanning electron micrographs, the nanoparticles had a spherical or ellipsoidal shape, and a slight agglomeration was observed. The appropriate ratio of CS/ECL-E was 1:3, in which an EE of 89.47%, a particle size of 256.05 ± 7.70 nm, a zeta potential of 40.37 ± 0.66 mV, and a PDI of 0.22 ± 0.05 were obtained. The nanoparticles also exhibited high antioxidant activities, as assayed by DPPH and ABTS radical scavenging activities, ferric reducing ability power (FRAP), and oxygen radical absorbance capacity (ORAC). Low minimum inhibitory concentration and minimum bactericidal concentration were observed against Pseudomonas aeruginosa (9.38, 75.00 mg/mL) and Shewanella putrefaciens (4.69, 75.00 mg/mL). In addition, ECL-E loaded in nanoparticles could maintain its bioactivities under various light intensities (1000–4000 Lux) for 48 h. Some interactions among TPP, CS, and ECL-E took place, as confirmed by FTIR analysis. These nanoparticles had the increased storage stability and could be used for inactivating spoilage bacteria and retarding lipid oxidation in foods.

Sucuk, Turkish-Style Fermented Sausage: Evaluation of the Effect of Bioprotective Starter Cultures on Its Microbiological, Physicochemical, and Chemical Properties

Bio-protection is one of the most popular natural protection methods to control food safety and shelf life. Lactic acid bacteria, especially Lactobacilli strains, are used in the food industry for this purpose due to their probiotic properties and, accordingly, bioprotective properties. We aimed to investigate the role of the bacteriocin-producing lactic acid bacteria Lactobacillus sakei and Pediococcus acidilactici in inducing microbiological, physicochemical, and chemical changes in the Turkish-style fermented sausage sucuk. The effects of protective cultures were compared with those of commercial starter cultures consisting of Pediococcus pentosaceus + Staphylococcus carnosus; a non-cultured group was used as a control. L. sakei inoculation and, to a lower extent, P. acidilactici inoculation resulted in the rapid domination of lactic acid bacteria (LAB) in the environment, whereas commercially used starter cultures and the non-cultured group showed lower counts of LAB. Moreover, L. sakei and P. acidilactici succeeded in inhibiting pathogens including S. aureus, E. coli, and Enterobacteriaceae. The number of enterococci decreased notably in the L. sakei-inoculated sucuk samples; however, an increase was determined in the samples inoculated with P. acidilactici. On the other side, the effect of commercial starter cultures was not sufficient for the inhibition of food-borne pathogens in the sucuk samples. Consequently, the inoculation of protective cultures, particularly of L. sakei, can provide a considerable contribution to improving microbial quality and food safety, retarding lipid oxidation, and increasing proteolytic activities in sucuk without important changes in its sensory properties.

Effect of wet media milling on starch-quercetin complex: Enhancement of Pickering emulsifying ability and oxidative resistance

This research explored the effect of media milling on complexation of corn starch (CS) and quercetin (QC), interaction mechanism and Pickering emulsifying ability of corn-quercetin (CS-QC) complex. CS-QC with QC/CS ratio of 1:24 had the highest encapsulation efficiency of 76.00 ± 1.30 %. Average volume-mean diameter, average whole molecular size (Rh) and debranchedamylopectinchain length of CS-QC were significantly decreased after milling. Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) spectra confirmed the complexation between CS and QC. Emulsifying capacity and emulsion stability of Pickering emulsion stabilized by 5 % CS-QC complex particles after 120 min milling reached 100.00 % and 100.00. Pickering emulsions stabilized by these complex particles demonstrated superior oxidative stability. These results demonstrated that media milling could be an efficient physical approach to obtain starch-polyphenol complex by enhancing non-covalent interactions, which could not only be used as food-grade Pickering emulsifiers, but also retard lipid oxidation.

From Waste to Consumption: Tomato Peel Flour in Hamburger Patty Production.

Tomato is a widely cultivated crop and its processing produces large quantities of wastes, such as pulp, seed, and peel. In recent years, the valorization of these wastes in the production of high-value-added food products has gained popularity in achieving environmental sustainability and zero waste. From this viewpoint, dried tomato peel (DTP-1%, 2%, 3%, 4%) flour was included in hamburger formulations. In patty samples, ash, carbohydrate, and dietary fiber amounts were increased due to the high fiber content of DTP flour, while moisture and fat percentages decreased with increasing amounts of DTP flour (p < 0.05). The inclusion of DTP flour retarded lipid oxidation during cooking (p < 0.05). The significantly highest cooking yield was calculated in samples including 4% DTP flour. In parallel, water-holding capacity, moisture, and fat retention values increased with increasing levels of DTP flour (p < 0.05). The enrichment of patties with DTP flour resulted in hard texture, less gumminess, and a darker, more reddish and yellowish color (p < 0.05). Hamburger samples containing 1% or 2% DTP flour were graded with closer scores in the sensory panel as compared to the control (0% DTP). Overall, our findings demonstrated that DTP flour up to 2% could be used to improve the nutritional and technological properties of patty samples.

Antioxidant and antibacterial effect of lemon verbena leaves’ (Lippia citriodora) extract as a natural preservative on refrigerated meat patties during storage

This study aims to determine the influence of adding lemon verbena leaf (LVL) extract on meat samples’ physicochemical, microbiological, and sensory properties. The ethanolic extracts (LVL-1, LVL-2, LVL-3, and LVL-4) revealed higher (p ≤ 0.05) content of phenolics and flavonoids than the aqueous extract (LVL-5). Then, LVL-1 extract was selected for antioxidant activity (DPPH) analysis (75.73%). LVLs’ ethanolic extracts at concentrations of 0.0%, 0.5%, and 1.0% were added to meat samples. Redness parameters and organoleptic properties were significantly affected. However, LVL-1.0% was more efficient in reducing microbial growth up to day 12 of the storage period; therefore, 0.5% LVL reduced discoloration and lipid oxidation without affecting organoleptic properties. Cooking yield and hardness were decreased effectively at a concentration of LVL-1.0%. LVL extract effectively delayed the lipid oxidation of meat samples. Redness parameters were affected, and this was also noted in sensory analysis. Adding 0.5% (LVL-0.5%) revealed high efficiency in retarding lipid oxidation and improving color stability in meat samples. In addition, no significant difference in sensory characteristics was identified between the experimental group and control treatments. Despite the beneficial effects on the fat peroxidation of meat patties, no level of LVL extract could delay microbiological degradation during storage at 4°C for 12 days. In this context, LVL extract is an alternate technique for producing meat and meat products with lower synthetic conservatives. Therefore, adding 0.5% LVL extract reduced discoloration and lipid oxidation without impacting sensory parameters, making it a viable option for processing meat samples. Finally, because no significant impacts (p ≥ 0.05) were found during the storage period when higher concentrations were utilized (LVL-1.0 %), the addition of LVLs (LVL-0.5%) is more recommended for application in meat and meat products.

Effect of Stevia rebaudiana stem waste extract on lipid oxidation of salted-dried Pacific saury during chilled storage

Lipid oxidation is the major form of deterioration in salted-dried fish during storage. We here studied the use of Stevia rebaudiana stem (SRS) waste for impeding lipid oxidation of salted-dried Pacific saury fillets during chilled storage. Compared with Vitamin C (VC), the SRS extract (0.2%) significantly delayed lipid oxidation of the salted-dried fish, as determined through assays of the peroxide value, conjugated diene, thiobarbituric acid reactive substances, and acid value; VC is commonly used in salted-dried products. The color results further confirmed the feasibility of the SRS extract in maintaining the quality of the salted-dried Pacific saury fillets. The antioxidant mechanism studies unveiled that the SRS extract exhibited a higher Fe2+-chelating ability than VC, whereas the extract exhibited lower DPPH and ABTS radical-scavenging abilities than VC. This indicated that the high efficacy of the SRS extract in retarding lipid oxidation may be attributable to its higher Fe2+-chelating ability. The in situ Fe2+-chelating assay conducted using confocal laser scanning microscopy further confirmed this conclusion. Potential functional phenolic compounds in the SRS extract were then profiled using the LC-MS method. The SRS waste extract can thus be applied as a natural antioxidant for delaying lipid oxidation of salted-dried fish.

Effects of clove bud oil on the physicochemical properties and oxidative stability of canola oil organogels structured by different beeswax contents.

The aim of this study was to investigate the utilization of clove bud oil as fat-soluble antioxidants for retarding lipid oxidation in organogels by structuring canola oil with beeswax at 5, 7.5, and 10% concentration under accelerated oxidation condition. Oil binding capacity and viscoelastic properties were increased with beeswax content, but were not nearly affected by the addition of clove bud oil. Organogel loaded with clove bud oil were found to be more effective in retarding lipid oxidation in high beeswax content systems, particularly evident in 10% beeswax samples. The addition of clove bud oil resulted in low levels of hyeoperxide and MDA, and protected against texture and color deterioration during the storage period. Additionally, the Pearson correlation between lipid oxidation indices and parameters of texture and color has been found to exhibit a limited association, with the exception of the a* and b* values, which show a strong correlation.

The combined effect of vacuum-skin packaging and oxygen absorbers on the color stability and physicochemical properties of wet-aged Chikso beef

Beef discoloration during wet aging is mainly attributed to deoxymyoglobin or metmyoglobin accumulation. We applied advanced packaging methods including vacuum-skin packaging, oxygen absorbers, and their combination to maintain color stability and physicochemical attributes of Chikso beef during aging. Meat blocks from semimembranosus muscle were assigned to a 2 × 2 factorial arrangement that involved two packaging types (conventional vacuum packaging and vacuum-skin packaging) and the presence of oxygen absorbers (exclusion or inclusion) inside a package. After packaging, samples were wet-aged for 28 days. Addition of oxygen absorbers significantly increased beef color stability. Vacuum-skin packaging significantly increased metmyoglobin reducing activity and retarded lipid oxidation of beef. Moreover, their combination significantly prevented visual beef discoloration evaluated by panelists. Therefore, combination of these two packaging technologies could be effective in maintaining color stability and physicochemical attributes of Chikso beef during aging.

Effect of edible coating containing Aloe vera extracts on the oxidative stability and quality parameters of cooked ground chicken meat

This study investigated the impact of incorporating Aloe vera gel (AVG) and Aloe vera leaf skin (AVLS) extracts into edible coating (EC) on retarding lipid oxidation and enhancing the quality characteristics of cooked ground chicken meat during 14 days of storage at 4 °C. The results indicated that both AVG and AVLS extracts had a similar amount of total phenolic contents. EC application resulted in a decrease in pH values, and an increase in aw values. The addition of 2% AVG or AVLS extracts into EC formulation also decreased TBARS and ORP values. Although textural properties were not affected by EC application containing AVG or AVLS extracts, this application retarded L*, a*, and b* color values. The results indicated that Aloe vera extracts may be incorporated into EC by processors to improve lipid oxidation inhibition and maintain the quality characteristics of poultry meat products during refrigerated storage.

Use of olive and sunflower protein hydrolysates for the physical and oxidative stabilization of fish oil-in-water emulsions.

Olive and sunflower seeds are by-products generated in large amounts by the plant oil industry. The technological and biological properties of plant-based substrates, especially protein hydrolysates, have increased their use as functional ingredients for food matrices. The present study evaluates the physical and oxidative stabilities of 50 g kg-1 fish oil-in-water emulsions where protein hydrolysates from olive and sunflower seeds were incorporated at 20 g kg-1 protein as natural emulsifiers. The goal was to investigate the effect of protein source (i.e. olive and sunflower seeds), enzyme (i.e. subtilisin and trypsin) and degree of hydrolysis (5%, 8% and 11%) on the ability of the hydrolysate to stabilize the emulsion and retard lipid oxidation over a 7-day storage period. The plant protein hydrolysates displayed different emulsifying and antioxidant capacities when incorporated into the fish oil-in-water emulsions. The hydrolysates with degrees of hydrolysis (DH) of 5%, especially those from sunflower seed meal, provided higher physical stability, regardless of the enzymatic treatment. For example, the average D [2, 3] values for the emulsions containing sunflower subtilisin hydrolysates at DH 5% only slightly increased from 1.21 ± 0.02 μm (day 0) to 2.01 ± 0.04 μm (day 7). Moreover, the emulsions stabilized with sunflower or olive seed hydrolysates at DH 5% were stable against lipid oxidation throughout the storage experiment, with no significant variation in the oxidation indices between days 0 and 4. The results of the present study support the use of sunflower seed hydrolysates at DH 5% as natural emulsifiers for fish oil-in-water emulsions, providing both physical and chemical stability against lipid oxidation. © 2024 Society of Chemical Industry.

Ethanolic cashew leaf extract: Antioxidant potential and impact on quality changes of dried fermented catfish during storage

Ethanolic cashew (Anacardium occidentale, L.) leaf extract (ECLE) rich in phenolic compounds was prepared with the aid of ultrasonication. Impacts of light, heat, and pH on stability of antioxidant activity of ECLE were investigated. Exposure to light at an intensity of 1000 lx for 24 h showed no effect on activity of ECLE (p > 0.05). When being exposed to light for an extended periods (48 h), total phenolic content (TPC) became lower (p < 0.05). Light intensities at 2400–4000 lx for 24 h significantly decreased TPC and reduced antioxidant activities (p < 0.05). Thermal treatment at 60–100 ̊C for 1 h plausibly induced decomposition and simultaneously released low-molecular-weight phenolic compounds, leading to an increase in activity (p < 0.05). ECLE showed the augmented antioxidant activity in pH range of 3–5. When ECLE was added to dried fermented catfish (DFC) at 200–600 mg/kg and stored for 21 days at 30 ̊C, ECLE at 600 mg/kg effectively retarded lipid oxidation and inhibited the growth of microorganisms of DFC during storages, thereby extending the shelf life of DFC. ECLE could therefore be utilized as natural food additive or preservative in DFC.

Impact of antioxidant potential of rohu (Labeo rohita) swim bladder gelatin hydrolysate on oxidative stability, textural and sensory properties of fish sausage enriched with polyunsaturated fatty acids.

The impact of rohu swim bladder gelatin hydrolysate (SBGH) at different levels on textural, sensory, oxidative, and microbial properties of polyunsaturated fatty acids enriched rohu fish cooked sausages (PUFA-RFS) were investigated in the current study. SBGH addition enhanced the lightness values of PUFA-RFS compared to both control sausages (without SBGH and with butylated hydroxyanisole (BHA) (P > 0.05). PUFA-RFS added with 3% SBGH exhibited higher hardness, cohesiveness, and gumminess throughout the storage duration at both 4°C and -20°C temperatures when compared to other sausages counterparts. PUFA-RFS added with SBGH displayed lower PV, TBARS, and total microbial counts than the control sausages. Furthermore, PV, TBARS, and total microbial count values of sausage decreased with an increase in SBGH level, indicating retardation in lipid oxidation and microbial growth by SBGH in a dose-depended manner. Nevertheless, sausage added with 3% SBGH had higher overall acceptability than other sausage counterparts. Therefore, SBGH could retard lipid oxidation and improves textural properties of PUFA-enriched fish sausage.

Improving the quality of multi-layer films based on furcellaran by immobilising active ingredients and impact assessment of the use of a new packaging material.

To improve the quality of multi-layer film, four-layer films based on furcellaran and active ingredients: gelatin hydrolysate, curcumin, capsaicin, montmorillonite and AgNPs, were produced in an innovative manner. The films were characterised by SEM and AFM analysis. Along with an increase in the concentration of active ingredients, the structure of the film becomes less homogeneous, which may affect the functional properties. The objective of the study was to analyse changes in the functional properties of the newly-obtained films and to verify their potential as packaging materials for fish products. With the increase in active ingredient concentration, water properties also improved, but there were no noticeable significant effects on mechanical properties. For antioxidant properties, the obtained values were within 1.04-2.74mM Trolox/mg (FRAP) and 7.67-40.49% (DPPH). The obtained multi-layer films were examined with regard to the shelf-life of salmon. For this purpose, salmon fillets were packed in films having good antioxidant and functional properties. The films were effective in microorganism growth inhibition responsible for fillet spoilage during storage. The microorganism number in the active film-stored samples was lower by 0.13 log CFU/g on day 12 versus the control. However, film application did not retard lipid oxidation in the salmon fillets. Nonetheless, the films show great potential as active packaging materials, extending the shelf-life of the packed foods.

Enhancing the quality of Havarti cheese: Chitosan films with nettle Urtica dioica L. extract as slice separators to retard lipid oxidation

The aim of this study was to develop an active slice separator based on a chitosan film with nettle extract (Ch_NE) for vacuum-packed Havarti cheese and to evaluate the changes during storage for 45 days at 5 °C. The active properties of the developed slice separator film were evaluated by measuring antioxidant and optical properties of the cheese and the film, as well as lipid oxidation of the cheese. The addition of nettle extract to chitosan films caused a decrease in mechanical properties such as tensile strength from 58.02 to 1.81 MPa and Young's Modulus from 1535.92 to 4.43 MPa, making them easy to apply and handle as slicing separators. Furthermore, the thermal properties of the films indicated their stability at temperatures commonly encountered during food heat processing. After 45 days of refrigerated storage, the Ch_NE slice separator demonstrated a significant reduction in thiobarbituric acid reactive substances in cheese samples, indicating a 56% decrease in lipid oxidation compared to the control group. In conclusion, an environmentally friendly alternative to synthetic and non-biodegradable slice separators have been successfully developed using chitosan, a by-product of the fish industry, enriched with an extract from nettle, a widely distributed wild plant.

Phycocyanin/tannic acid complex nanoparticles as Pickering stabilizer with synergistic interfacial antioxidant properties

This study reported a type of phycocyanin (PC)-tannic acid (TA) complex nanoparticles (NPs) fabricated by simply mixing PC with TA at appropriate mass ratios. The assembly of PC-TA NPs was driven by secondary forces involving hydrophobic interactions and hydrogen bonding. PC-TA NPs promoted formations of Pickering emulsions with an oil volume fraction (φ) of 0.1–0.8. The interfacial antioxidant ability of PC-TA NPs was evaluated by comparing the contents of hydroperoxides, malonaldehyde, and hexanal due to lipid oxidation. The results showed that PC-TA NPs retarded lipid oxidation more efficiently than did PC, TA, tween 20, or tween 80, which suggested the synergistic antioxidant action of PC and TA. Besides, the PC-TA NPs stabilized high internal phase emulsion facilitated a higher retention of β-carotene under UV irradiation. Altogether, our findings demonstrate that the modification of PC by TA represents a strategy to fabricate PC-TA NPs with enhanced emulsification and antioxidant efficiency.

Curcumin-mediated photodynamic treatment extends the shelf life of salmon (Salmo salar) sashimi during chilled storage: Comparisons of preservation effects with five natural preservatives

The impact of curcumin-mediated photodynamic treatment (PDT) on the microbiological, physicochemical and sensory qualities of salmon sashimi has not been explored. Herein, this study aimed to evaluate the effects of PDT on the shelf-life quality of ready-to-eat salmon fillets during chilled storage (4 °C) in comparison with five widely investigated natural extracts, including cinnamic aldehyde, rosmarinic acid, chlorogenic acid, dihydromyricetin and nisin. From a microbial perspective, PDT exhibited outstanding bacterial inhibition, the results of total viable counts, total coliform bacteria, psychrotrophic bacteria, Pseudomonas spp., Enterobacteriaceae family, and H2S-producing bacteria were notably inactivated (p < 0.05) to meet the acceptable limits by PDT in comparison with those of the control group and natural origin groups, which could extend the shelf-life of salmon fillets from<6 days to 10 days. In the alteration of physicochemical indicators, PDT and natural extracts were able to maintain the pH value and retard lipid oxidation in salmon fillets, while apparently slowing the accumulation (p < 0.05) of total volatile basic nitrogen and biogenic amines, especially the allergen histamine, which contrary to with the variation trend of spoilage microbiota. In parallel, PDT worked effectively (p < 0.05) on the breakdown of adenosine triphosphate and adenosine diphosphate to maintain salmon fillet freshness. Additionally, the physical indicators of texture profile and color did not have obvious changes (p < 0.05) after treated by PDT during the shelf life. Besides, the sensory scores of salmon samples were also significantly improved. In general, PDT not only has a positive effect on organoleptic indicators but is also a potential antimicrobial strategy for improving the quality of salmon sashimi.

Antioxidant Potential of Spray- and Freeze-Dried Extract from Oregano Processing Wastes, Using an Optimized Ultrasound-Assisted Method.

Origanum vulgare is recognized worldwide for its numerous applications, in the food industry and beyond. However, the extraction of its essential oils generates a significant amount of waste. The aim of this research was to achieve the valorization of solid waste from oregano hydro-distillation, by (i) optimizing the ultrasound extraction of antioxidants, (ii) evaluating the effect of spray and freeze drying on the extract's physicochemical properties, and (iii) characterizing the obtained powder by its antioxidant capacity. A central composite design of experiments was used to optimize the sample/solvent ratio, ethanol/water ratio, and extraction time. The extract was analyzed for its antioxidant potential by determining the percentage of DPPH inhibition, FRAP, and total phenolic content (TPC). The GAB model best fit the data for the moisture sorption isotherm of the resulting powder. The antioxidant activity of the powders was tested in a ground-beef food system. The TPC was maximized at times longer than 58 min, a sample/solvent ratio between 0.058 and 0.078, and a ratio of ethanol/water around 1. Neither drying method significantly affected the antioxidant properties of the extract, even though the resulting powders from each showed a different morphology (determined using SEM). Encapsulation with maltodextrin protected the spray-dried extract during a 6-month storage period. Powders from both drying methods equally retarded lipid oxidation, and were comparable to the synthetic antioxidant BHT. It is concluded that oregano processing waste is a potent source of antioxidants, and that its dried extract, via an ultrasound-assisted process, can potentially be used as a natural alternative to synthetic antioxidants.

Antioxidant activity of selected plants extract for palm oil stability via accelerated and deep frying study

Antioxidants are organic compounds that help to prevent lipid oxidation and improve the shelf-life of edible oils and fats. Currently, synthetic antioxidants were used as oil stabilizing agent. However, synthetic antioxidants have been causing various health risks. As a result, natural antioxidants such as most parts of olive plant, green tea, sesame, medicinal plants were plays an important role to retard lipid oxidation. The palm oil was continuously frying at 180 °C for 6 days using Lepidium sativum (0.2%w/v) and Aframomum corrorima (0.3%w/v) seeds extracts as antioxidant. The physicochemical properties of oil in the herbal extract additive group significantly maintained the oil quality during frying compared to the normal control and the food sample containing group. The L. sativum extract had a greater oil stability compared to A. corrorima extract. However, the frying oil without herbal extract significantly increase the physicochemical properties of oil such as iodine value, acid value, free fatty acid, total polar compounds, density, moisture content, pH etc. during repetitive frying. The antioxidant activity of the plant extract was outstanding, with an IC50 value in the range of 75–149.9 μg/mL when compared to the standard butyl hydroxy anisole, which had an IC50 value in the range of 74.9 ± 0.06–96.7 ± 0.75 μg/mL. The total phenolic and flavonoid content of the extract for L. sativum was 128.6 ± 0.00 mg GAE/g, 127.0 ± 0.00 mg QE/g, and 130.16 ± 0.001 mg GAE/g, 105.76 ± 0.02 mg QE/g, respectively. The significant effect of the plant extract on the degradation of oil and the formation of free fatty acids was confirmed by Fourier transform infrared spectroscopy. The result of these study revealed that the ethanolic crude extract of L. sativum and A. corrorima had a potential natural antioxidant to prevent the degradation of palm oil.

Reverse microemulsions as nano-carriers of tea polyphenols retard oxidation of Eucommia ulmoides oliver seed oil

Eucommia ulmoides Oliver seed oil, rich in polyunsaturated fatty acids (PUFAs), is susceptible to lipid oxidation in foods. Tea polyphenols (TPs) may effectively retard lipid oxidation in non-polar systems according to the polar paradox theory. In this study, we constructed a TPs-loaded water-in oil (W/O) microemulsion, which is a transparent, spontaneously formed, and thermodynamically stable colloidal system. This system consisted of E. ulmoides oil (38%, w/w), Span80, Tween 80, 1,2 propanediol, water, and TPs (3%, w/w). TPs were encapsulated in water cores of microemulsion, endowing this system with the higher oxidative stability and radical scavenging abilities. The accelerated oxidation assay demonstrated that low-dose TPs (<0.5%, w/w) were more effective in retarding lipid oxidation than that of high-dose TPs. Within 56 d, the peroxide value of TPs-loaded microemulsion increased to 16.479 meq/kg oil at 65 ℃ and that of E. ulmoides oil exceeded the Food Safety standards value within only 45 d. These findings indicate that TPs encapsulated into microemulsion effectively inhibit PUFA-rich oil oxidation. The nano-scale W/O dispersed system favors the protection and practical application of natural water-soluble antioxidants in PUFAs-rich lipid foods.

Physical and Oxidative Stabilization of Oil-In-Water Emulsions by Roasted Coffee Fractions: Interface- and Continuous Phase-Related Effects.

Emulsions fortified with polyunsaturated fatty acids are highly relevant from a nutritional perspective; however, such products are prone to lipid oxidation. In the current work, this is mitigated by the use of natural antioxidants occurring in coffee. Coffee fractions with different molecular weights were extracted from roasted coffee beans. These components were positioned either at the interface or in the continuous phase of emulsions where they contributed to emulsion stability via different pathways. Coffee brew as a whole, and its high-molecular-weight fraction (HMWF), was able to form emulsions with good physical stability and excellent oxidative stability. When added post-homogenization to the continuous phase of dairy protein-stabilized emulsions, all coffee fractions were able to slow down lipid oxidation considerably without altering the physical stability of emulsions, though HMWF was more effective in retarding lipid oxidation than whole coffee brew or low-molecular-weight fraction. This is caused by various effects, such as the antioxidant properties of coffee extracts, the partitioning of components in the emulsions, and the nature of the phenolic compounds. Our research shows that coffee extracts can be used effectively as multifunctional stabilizers in dispersed systems leading to emulsion products with high chemical and physical stability.