Converting Food Waste into Value-Added Products: A Review on Current Technologies, Challenges, and Future Perspectives

Food waste has emerged as one of the most pressing global sustainability challenges because of its environmental, economic, and social implications. Nearly one-third of the food produced worldwide is lost or wasted each year, contributing to greenhouse gas emissions, depletion of natural resources, and increasing food insecurity. Advances in circular bioeconomy concepts and sustainable processing technologies have transformed food waste from an environmental liability into a valuable feedstock for producing biofuels, bioplastics, bioactive compounds, functional ingredients, prebiotics, and other high-value products. This review critically examines current strategies for converting food waste into value-added products, including green extraction technologies and biochemical, thermochemical, enzymatic, and microbial approaches. Attention is given to major agri-food by-products, such as fruit pomace, vegetable residues, oilseed meals, dairy by-products, and agro-industrial wastes. Emerging developments involving biorefinery concepts, artificial intelligence, digital biorefineries, synthetic biology, and carbon-neutral production systems are also discussed. Furthermore, the review highlights recent applications of waste-derived fibers, antioxidants, and polyphenols in functional foods, especially bakery products. Finally, key challenges related to feedstock heterogeneity, process scalability, regulatory frameworks, economic feasibility, and sustainability assessment are critically analyzed together with future research directions supporting the transition toward resilient circular bioeconomy systems.