From waste to plate: valorization of fish by-products into functional collagen for circular gastronomy applications

One promising route for advancing the circular gastroeconomy is the conversion of fish byproducts into high value functional ingredients. This study aimed to transform fish side streams from culinary settings, such as hotels, into collagen that can be reintroduced into the food system. To evaluate its culinary potential, the extracted collagen was incorporated into citrus gels and emulsified sauces at varying concentrations (0–1.5%). Consumer acceptance was assessed using hedonic and Just-About-Right scaling, while circularity metrics were used to quantify potential waste diversion. The results show that collagen increased overall liking, improved mouthfeel, and enhanced textural properties, with optimal sensory acceptance observed at 1.0% collagen addition. At this concentration, overall liking scores increased from 6.5 to 7.8, while emulsion phase separation decreased from 12 to 4%. This study demonstrates that collagen derived from fish byproducts provide both functional and sensory benefits, while also contributing to measurable sustainability outcomes. Using fish byproducts sourced from a single 1,000person wedding, the study demonstrated reductions in waste, greenhouse gas (GHG) emissions, and resource loss. Overall, the findings suggest that valorizing fish side streams within the hospitality sector represents a scalable strategy to enhance flavor, texture, guest experience, and environmental performance transforming underutilized biomass into a circular, high impact ingredient stream.