A comprehensive review of fish protein hydrolysates targeting pet food formulations

The fish industry generates significant amounts of fish by- and co-products (FBCPs) annually, projected to reach 160.8 million tonnes by 2030. This growth highlights the urgent need for sustainable FBCP management and an opportunity to improve the sector's environmental sustainability. Fish protein hydrolysates (FBCPHs) and bioactive peptides (BPs) derived from these FBCPs are gaining recognition in the pet food sector for their nutritional and bioactives benefits. FBCPHs, primarily sourced from category 3 by-products unsuitable for human consumption, could significantly enhance the economic viability of both industries. This review analyzes production processes, highlighting the benefits and challenges of enzymatic hydrolysis and reviewed emerging technologies such as subcritical water hydrolysis (SWH), which are promising sustainable alternatives by enhancing extraction efficiency and reducing energy consumption. The review explores FBCPHs' applications in pet food, focusing on beneficial biological activities (e.g. antioxidant, prebiotic, neuroprotective). Findings show FBCPHs have significant potential in pet food formulations, providing palatability, hypoallergenic benefits, and addressing health concerns like gastrointestinal disorders and stress-related behaviors. However, further research is required to optimize production processes, scale industrial application, and ensure regulatory compliance. In conclusion, FBCPHs present a valuable solution for promoting sustainability, improving pet nutrition, and supporting the circular economy.