Extraction, characterization and functional properties of gelatin from fish skin and scales of Tilapia and Cobia

Abstract

Fish derived gelatin has gained recognition as a sustainable and culturally acceptable alternative to bovine and porcine gelatin particularly in food, pharmaceutical and biomedical applications. This study explores the extraction, characterization and functional evaluation of gelatin obtained from the skin and scales of Oreochromis mossambicus (tilapia) and the skin of Rachycentron canadum (cobia). The gelatin was extracted via acid thermal hydrolysis and assessed for its proximate composition, gel strength, viscosity, water and oil holding capacities, foaming capacity, emulsifying properties and physicochemical attributes. Tilapia skin gelatin showed the highest protein content (92.1±1.1%), superior gel strength (255 g Bloom) and favourable emulsification and foaming characteristics compared to scale and cobia gelatins. The amino acid profile revealed high glycine, proline and hydroxyproline levels and supporting its structural stability and gel forming potential. Microbiological analysis confirmed the safety of the gelatin and sensory evaluation of gelatin based jelly indicated good consumer acceptability. These results underscore the viability of utilizing aquaculture by-products for high quality gelatin production, supporting waste valorization and sustainable processing in the fisheries sector.