Gelatin hydrolysate from blacktip shark skin prepared using papaya latex enzyme: Antioxidant activity and its potential in model systems

Antioxidant activities of gelatin hydrolysates from blacktip shark skin prepared using papaya latex enzyme with different degrees of hydrolysis (DHs: 10%, 20%, 30% and 40%) were evaluated. All antioxidant activity indices of hydrolysates increased with increasing DH (P < 0.05). When gelatin hydrolysate with 40%DH was determined for its pH and thermal stability, ORAC and chelating activity remained constant or slightly increased in a wide pH range (1-9) and during heating (100 °C) for 240 min. It was also stable in simulated gastrointestinal tract model system. Moreover, gelatin hydrolysate at a level of 500 and 1000 ppm could inhibit lipid oxidation in both β-carotene linoleate and cooked comminuted pork model systems. Therefore, gelatin hydrolysate from blacktip shark skin (40%DH) can potentially be used as an alternative source of natural antioxidants.