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.

Use of mushrooms as antioxidants in a lipid oxidation model under indirect and direct oxidation tests: ethanolic extracts of Ganoderma resinaceum and Phlebopus bruchii.

BACKGROUND: Foods contain lipids that are easily susceptible to oxidation, which can modify their sensory properties. Although these compounds provide characteristic flavours and odours, there are also unwanted compounds, such as volatile secondary oxidation products, representing a recurring problem for both the industry and consumers. Synthetic antioxidants are often employed to prevent this but their chronic consumption can be detrimental to human health. The present study evaluates the antioxidant potential of ethanolic extracts from Ganoderma resinaceum and Phlebopus bruchii using an accelerated oxidation test. RESULTS: The composition profile of the extracts was investigated, identifying the presence of tryptophan, quinic acid, caffeic acid and 3,4-dihydroxyphenylglycol-phenolic acid. The antioxidant capacity of the extracts was compared with that of butylated hydroxytoluene (BHT) in sunflower oil that was oven-heated at 60 °C. Chemical (peroxide value, p-anisidine value and conjugated dienes) and volatile (2-octenal, 2-heptenal and 2,4-decadienal) indicators were measured over 28 days. The peroxide value decreased for both extracts at a similar level to that of BHT 0.02% w/w, and conjugate dienes decreased in the presence of G. resinaceum 0.1% w/w. Meanwhile, p-anisidine exhibited a slightly greater decrease for P. bruchii 0.1% w/w than for BHT. The sample with 0.1% w/w of extracts showed a reduction in volatile secondary oxidation compounds, indicating significant antioxidant activity. CONCLUSION: Based on these results, both extracts could be proposed as potential antioxidants in foods with a high lipid content. © 2024 Society of Chemical Industry.

Microencapsulation of phenolic compounds extracted from soybean seed coats by spray-drying.

This study aimed to characterize and microencapsulate soybean seed coats phenolic compounds by spray-drying, evaluating physicochemical properties and storage stability. Different extraction methodologies were used to obtain crude extract (SCE), ethyl acetate fraction, water fraction, and bound phenolic extract. Extraction yield, total phenolic and flavonoid contents, and antioxidant capacity were determined. HPLC-electrospray ionization source-MS/MS analysis was performed on SCE. Microencapsulation by spray-drying of SCE incorporating 10%, 20%, and 30% maltodextrin (MD) was carried out. Drying yield (DY), encapsulation efficiency (EE), moisture, morphology and particle size, dry, and aqueous storage stability were evaluated on the microcapsules. SCE had 7.79 g/100 g polyphenolic compounds (mainly isoflavones and phenolic acids) with antioxidant activity. Purification process by solvent partitioning allowed an increase of phenolic content and antioxidant activity. Microcapsules with 30% MD exhibited the highest DY, EE, and stability. Microencapsulated polyphenolic compounds from soybean seed coats can be used as functional ingredients in food products. PRACTICAL APPLICATION: Soybean seed coat is a usually discarded agro-industrial by-product, which presents antioxidant compounds of interest to human health. These compounds are prone to oxidation due to their chemical structure; therefore, microencapsulation is a viable and reproducible solution to overcome stability-related limitations. Microencapsulation of soybean seed coats polyphenols is an alternative which protects and extends the stability of phenolic compounds that could be potentially incorporated into food products as a natural additive with antioxidant properties.

Comparative study of accelerated assays for determination of equivalent days in the shelf life of roasted high oleic peanuts: Chemical and volatile oxidation indicators in accelerated and room temperature conditions.

Lipids present in peanuts are susceptible to oxidation, which affects food quality and safety, for this reason shelf-life studies are carried out. The objective was to determine the relation between accelerated oxidation conditions and room temperature storage for roasted peanuts. Lipid oxidation indicators and roasted flavour volatiles were measured. There was a negative correlation between roasted and oxidation volatiles. In this research, 2,5-dimethylpyrazine and 2-ethyl-3,6-dimethylpyrazine were good indicators of the storage conditions of roasted peanuts, and the peroxide value (PV) was the most important oxidation indicator. For the comparision of equivalent days, it was used the peroxide value which reached 7.90, 2.47 and 0.89 Meq.O2/kg after 21 days at 25, 45 and 60 °C, respectively. The accelerated storage condition of 60 °C is optimal for estimation of the shelf life at 25 °C wherein 1 day at 60 °C is equal to 8.79 days at 25 °C.

Rheological Behavior, Antimicrobial and Quorum Sensig Inhibition Study of an Argentinean Oregano Essential Oil Nanoemulsion.

In this study, Argentinean oregano essential oil (OEO) nanoemulsions (NEs) were developed. Four NEs were prepared: a control (CNE), EONE1 (10.6 mg EO/g NE), EONE2 (106 mg EO/ g NE), and EONE3 (160 mg EO/g NE) and tested for antimicrobial activity against Staphylococcus aureus ATCC 13565, Listeria monocytogenes Scott A, Pseudomonas aeruginosa ATCC 14213, and Escherichia coli O157:H7 using a broth microdilution assay and quorum sensing inhibition in a model using Chromobacterium violaceum ATCC 12472, where the production of violacein was quantified. The chemical composition of the EO was determined by gas chromatography-mass spectrometry. The average particle size (nm) and polydispersity index were monitored over 14 days at two different storage temperatures (4 and 23°C). A rheological behavior study was carried out using a dynamic shear rheometer, and flow curves, as well as viscoelastic properties, were determined. E. coli and L. monocytogenes were the most sensitive microorganisms to EONE (MIC of 2 and 5 mg/ml for EOEN3). Sub-MICs for NE were found at lower concentrations than those for pure EO. A significant reduction in violet pigment intensity and colorless coloration (p < 0.05) were observed at different NE concentrations concerning the control sample. The flow behavior index (n) decreased, and the consistency index (k) increased when the EO concentration was increased. CNE, EONE1, and EONE2 showed liquid-like behavior (G' < G″) in the low-frequency region, whereas a solid-like behavior (G' > G″) was observed in the high-frequency region, presenting a viscoelastic behavior, appearing as a wormlike micellar solution. For EONE3, a strong increase in both moduli was observed with increasing OEO concentration. The G' was about one order of magnitude higher than the G″ over the whole frequency range, indicating the presence of a gel-like structure. The incorporation of EOs into an NE increased their stability, lowering the particle size, leading to a wormlike micelle with higher viscosity. Moreover, this NE had good antimicrobial activity and novel quorum-sensing inhibition activity. The results of this study indicated that Argentinean OEO NE could be used in a food system as a natural and stable antimicrobial agent.

A Natural Peanut Edible Coating Enhances the Chemical and Sensory Stability of Roasted Peanuts.

This study aims to assess the enhancement of the chemical and sensory properties of roasted peanuts during storage, through the application of high-protein defatted peanut flour (DPF) coatings incorporated with and without antioxidants. The control sample without coating, packed in normal atmosphere (control), showed the highest conjugated dienes (CD) increment (from 1.17 on day 0 to 3.60 on day 180). Roasted peanuts without coating, packed in high barrier bags under vacuum, reached the lowest CD at day 180 (1.92). Conjugated trienes and peroxide values were analogous to CD. The control exhibited the greatest decrease in α-tocopherol (from 27.65 mg/100 g on day 0 to 21.32 mg/100 g on day 180) and γ-tocopherol (from 21.91 mg/100 g on day 0 to 14.99 mg/100 g on day 180). 3-Methylpyridine and 2,5-dimethylpyrazine decreased with storage time only for the control, which had the highest increase in oxidized flavor (from 0 on day 0 to 13.30 on day 180), cardboard (from 7.67 on day 0 to 15.23 on day 180), and astringency. The lowest decreases in roasted peanutty scores were seen in coated samples. DPF coatings delayed roasted peanuts oxidation, enhancing their sensory properties and shelf life compared with the control sample. PRACTICAL APPLICATION: Defatted peanut flour (DPF) is a byproduct obtained during peanut oil extraction and is a possible material for edible film preparation. This strategy adds value to the peanut industry by transforming a by-product into a material with the potential to develop biodegradable and economical films. The application of this DPF-based edible coating on the surface of roasted peanuts may have contributed to extent product's shelf life, allowing for coated products to be packaged in lower barrier and less expensive materials. Use of peanut material to coat peanuts avoids the risk of allergen protein cross contamination, which would be highly valuable for the food industry.

Sensory and Chemical Stabilities of High-Oleic and Normal-Oleic Peanuts in Shell During Long-Term Storage.

Oxidative rancidity is one of the major causes of peanut quality deterioration. The in-shell nut industry's greatest concern is to preserve high quality and extended the shelf life of these products. This research determined the sensory and chemical stabilities of raw in-shell high-oleic and normal-oleic peanuts during long-term storage. In-shell peanuts samples of normal- and high-oleic types were stored at room temperature (23 °C) for 675 days. The quality parameters, like the fatty acid composition, moisture content, free fatty acids (FFA), peroxide value (PV), conjugated dienes (CD), and p-anisidine value (pAV), as well as sensory attributes, were analyzed every 45 days. High-oleic samples showed a 4.36-fold higher oleic acid/linolenic acid (O/L) ratio (O/L = 10.65) than normal-oleic peanuts (O/L = 2.44). FFA, PV, CD, pAV, and oxidized and cardboard flavors increased in all stored samples but especially in normal-oleic peanuts. Conversely, roasted peanutty flavor decreased in all samples during storage but in lower proportion in high oleic peanut samples. The sensory and chemical changes that occurred in unshelled normal- or high-oleic peanut samples were not remarkable, suggesting that the shell may protect peanut kernels against deterioration. However, in-shell high-oleic samples show greater stability and shelf life than normal-oleic peanuts under the studied storage condition. PRACTICAL APPLICATION: Quality preservation of peanuts is important for the food industry using peanuts as an ingredient. Peanut processors are concerned as to the best ways to preserve peanut quality for long-term storage. Raw high oleic peanuts kept in the shells show better preservation of their sensory and quality properties during storage. In-shell peanuts constitute an appropriate alternative to preserve chemical and sensory properties of this product.

Antioxidant activity of fractions from oregano essential oils obtained by molecular distillation.

The objective of this study was to determine the antioxidant activity of fractions separated from oregano essential oil by short-path molecular distillation. Two residue (R1 and R2) and two distillate (D1 and D2) fractions were prepared by molecular distillation. The major components were: carvacrol, terpinen-4-ol and γ-terpinene in R1 and R2; and γ-terpinene, α-terpineol and sabinene in D1 and D2. Free-radical scavenging activity was observed in all fractions and was highest in R2 (77.2%). D1 and D2 showed a smaller amount of volatile oxidation compounds produced from sunflower oil stored at 60°C for 14days. The greatest antioxidant activity was observed in D1 and D2. The thermal stability of oregano essential oil and its fractions was also analysed. R1 and R2 presented an increased carvacrol concentration and thermal stability. The short-path molecular distillation fractions can be used to prepare fractions from oregano essential oil with a higher antioxidant activity.