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 b-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.