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.