Valorizing neglected crop byproducts through eco-friendly techniques has gained attention as underutilized crops offer new sources of bioactive components. This study examined the chemical composition, phytochemicals, and antioxidant activities in six fractions of the underutilized chayote (Sechium edule). Each fraction was microwave-dried and extracted with ultrasound assistance. Shoots were high in ash and fiber, while pulp had high moisture and carbohydrates, and seeds were rich in fat and protein. Shoots, leaves, roots, and peels had high mineral levels, particularly Ca, K, Mg, P, Fe, and Zn. Shoots were also high in phenolics, flavonoids, and ascorbic acid, while leaves had a high carotenoid content. Polyphenol compounds such as myricetin and catechin were abundant in shoots, which exhibited the highest antioxidant activity. Chayote shoots, roots, and leaves are abundant in bioactive compounds that can be utilized in food and, therefore, offers an opportunity for utilization of a currently neglected plant byproduct.
Chitosan is mainly derived from seafood by-products and the thereof chitosan nanoparticles (CNPs) are known as nontoxic, biocompatible, biodegradable and functionalized nanostructures. CNPs, as green fillers, showed an appropriate potential in reinforcement of various biodegradable composites for food packaging and biomedical applications. After evaluation of different fabrication approaches and characterization techniques of CNPs, the changes in physical, mechanical, thermal, structural, morphological, and antimicrobial attributes of nanobiocomposites as a result of CNPs addition are discussed. The influence of bioactive loaded-CNPs and hybrid CNPs with metal nanoparticles, graphene, and montmorillonite in nanocomposites is also presented. Finally, the safety aspects of CNPs-loaded structures are highlighted to evaluate their implementation in food packaging and biomedical systems. It can be concluded that regardless of a few drawbacks, CNPs are promising nanomaterials to improve various operational, structural and antimicrobial properties of biocomposites for various applications in food packaging, delivery systems and biomedical uses.