Innovative approaches to food waste fermentation: turning waste into value at home and in industry

Food waste has emerged as a global environmental and economic challenge, creating an urgent need for sustainable waste management strategies. Among the most promising approaches, fermentation has gained increasing attention as a time-tested biotechnological process capable of converting food waste into value-added products. By transforming organic residues into useful resources, fermentation supports circular economy principles while reducing environmental impacts and improving resource efficiency. This review explores the principles, pathways, and practical applications of fermentation at both household and industrial levels. In domestic settings, fermentation enhances food preservation, improves nutritional value, and enables sustainable waste management through simple, low-cost methods. Key microbial agents such as lactic acid bacteria, yeasts, and molds play a critical role in transforming perishable foods into probiotic-rich, shelf-stable products. At the industrial scale, advanced fermentation technologies enable the conversion of agro-industrial by-products into value-added compounds such as biofuels (bioethanol, biogas, hydrogen), organic acids (lactic, acetic, propionic), enzymes, antioxidants, and natural aroma compounds. The review also highlights the environmental benefits of fermentation, including reductions in greenhouse gas emissions, nutrient recycling, and the generation of bioenergy, all of which align with circular economy principles. Despite its potential, challenges remain in terms of contamination control, feedstock heterogeneity, process scalability, and economic feasibility. Interdisciplinary collaboration spanning microbiology, engineering, policy, and economics is essential to overcome these barriers. Future perspectives emphasize the need for innovation, public engagement, and policy support to scale fermentation as a viable tool for sustainable food systems.