Production of protein hydrolysate from trout gelatine by enzymatic hydrolysis method and determination of its properties

Global fish production is estimated to reach 204 million tons in 2030. Fish waste is generated between 20% and 80% of fish from fish offered for human consumption, depending on their species and level of processing. More than 50% of these wastes are disposed of and cause environmental pollution. One of the valuable components found in these wastes is collagen protein. Although it is possible to use this unprocessed collagen as gelatin, there are alternatives for use in the food and cosmetics industry in the form of collagen hydrolysate. In this study, the production of collagen hydrolysate from gelatin produced from waste trout skins by using alcalase and flavourzyme enzymes by enzymatic hydrolysis method and the determination of its technological and bioactive properties were carried out. The degree of hydrolysis was determined as 18.30% in Alcalase hydrolysates and 3.25% in flavourzyme hydrolysates. The maximum ultraviolet absorption peaks of both hydrolysate samples were seen at a wavelength of 284 nm. In addition, the zeta potential values of both hydrolysate samples reached their maximum value at pH 9. The emulsion stability, foam capacity and stability of Alcalase hydrolysates are determined to be higher, while the emulsion activity ant oil binding capacity of flavourzyme hydrolysates are higher. However, DPPH radical scavenging activity (64.37%-73.41%) was found to be higher at all concentrations (15 mg/mL-30 mg/mL) of flavourzyme hydrolysates. When the results are evaluated, it is seen that both the technological and bioactive properties of hydrolysates obtained from trout gelatins offer opportunities for use in various sectors, especially in the food industry. As a result, a new alternative has been created for the evaluation of fish processing industry wastes generated as waste.