Valorization of Agricultural Food Waste as a Source of Bioactive Compounds: A Review of Applications in Nutraceuticals and Cosmetics

Abstract

Large amounts of by-products, such as peels, pomace, seeds, stalks, and spent substrates, are produced by the agri-food processing industry and are typically thrown away or, at most, recycled into compost or animal feed. However, these residues are becoming more widely acknowledged as a rich and underutilized source of bioactive substances with proven antioxidant, antibacterial, anti-inflammatory, and photoprotective qualities. These substances include polyphenols, carotenoids, dietary fiber, essential oils, and bioactive peptides. The main agricultural food-waste streams, citrus peel, grape pomace, apple pomace, tomato pomace, olive mill waste, spent coffee grounds, and banana peel, are summarized in this review, which also assesses both traditional and cutting-edge (green) extraction techniques for recovering their bioactive fractions. We look into downstream uses in cosmetics (anti-aging, UV-protective, and antibacterial formulations) and nutraceuticals (functional foods, dietary supplements), and we talk about the technological, legal, and financial obstacles that presently prevent widespread industrial use. The research indicates that, although further advancements in green extraction, standardization, and safety/regulatory frameworks are required to fully realize its promise, food-waste valorization constitutes a commercially promising and scientifically mature pillar of the circular bioeconomy.