Process Engineering Strategies for Enzyme‐ and Microbial‐Based Food Waste Valorization Towards Circular Food Manufacturing

ABSTRACT Food waste is a key sustainability issue in the world, and it leads to environmental pollution, inefficient use of resources, and financial loss. The concept of biological valorization has been identified as one of the promising approaches to transform food and agro‐industrial wastes into high‐value products in a circular bioeconomy and supports sustainable production systems. Although each of the studies has been conducted with the purpose of examining enzymatic or microbial processing alone, there is little in the way of an integrated insight into the combined and process‐engineered applications. This review gives a broad and process‐based view of what has been achieved in enzyme‐ and microbe‐assisted food waste valorization with an emphasis on the recent developments in enzymatic hydrolysis, microbial fermentation, and new hybrid platforms that combine these two catalytic systems through innovative manufacturing processes. Special attention is given to multi‐enzyme cascades, co‐culture fermentation, electrofermentation, and bioelectrochemical systems, which contribute to an increase in substrate conversion efficiency, product selectivity, and overall sustainability. Next‐generation techniques that are discussed in the review include the engineering of enzymes, microbial selection by metagenomics, genetically engineered microorganisms, and process optimization through artificial intelligence. In addition, urban biorefineries represent promising platforms for integrated waste management, enabling efficient conversion of food residues into value‐added bio‐based products. Combining enzymatic and microbial methods with contemporary process engineering mechanisms, this review suggests a comprehensive framework of systems design in creating an efficient system of biological valorization, which can guide researchers and industry to sustainable management of food waste and bioreactor product development.