Extraction Optimization and Physical Modification of Fish Gelatin from Thunnus tonggol Using Ultraviolet (UV) Irradiation

In this study, the yield of gelatin extraction from fish waste was optimized using response surface method. The highest yield was obtained with 0.8% citric acid concentration at 72.95 degrees C for 58 minutes. Then, fish gelatin was modified using ultraviolet radiation to overcome fish gelatin defects including unsuitable rheological properties and low thermo-stability. UV irradiation can create crosslinks via alkyl or phenyl groups of the proteins. The modified sample also showed the highest melting point due to the creation of cross-links and improved emulsification and foaming properties of fish gelatin through structural modification and increased surface hydrophobicity of gelatin.