Value-added chemicals from food supply chain wastes: state-of-the-art review and future prospects

Food wastes are generated massively across global food supply chains. Conventional treatments of food waste (e.g., landfilling and incineration) cause environmental, economic, and social problems. There is a more sustainable and profitable management option by valorization of food waste into value-added chemicals. Consumer chemicals, including acids, sugars, and their derivatized forms, can be synthesized from food waste. Refined specialty chemicals from food waste ranging from solvents to antioxidant materials can be important for nutraceutical and biomaterial applications. Meanwhile, commodity chemicals derived from food waste such as biofuel, biogas, and biochar help meet the global demand for large-scale reutilization of resources and energy. Niche chemicals (e.g., chitosan, glucose, and free amino nitrogen) converted from food waste also show great prospect in nutrient recycling and use for industrial applications. This paper reviews and discusses the latest technological advances in different physical, chemical, and biological treatments of food waste, such that the productivity of value-added chemicals and cost-effectiveness of these valorization methods can be improved for future scaled-up operations. This paper covers holistic comparison and in-depth discussion regarding the feasibility and sustainability of food waste derived chemicals, together with the market outlook of recycling and valorization of food wastes from state-of-the-art perspectives.