Effect of hydrolysing condition on antioxidant activity of protein hydrolysate from Crucian carp (Carassius carassius)

In this study protein hydrolysate was produced from the crucian carp using Alcalase 2.4L. The effect of temperature (40, 45, 50 and 55°C), time (60, 90, 120, 150, 180 & 21 min) and enzyme/substrate (Protein) at ratio of (30, 60 and 90 Anson unit), on degree of hydrolysis and antioxidant activity of product were investigated in a in a completely randomized design. The highest degree of hydrolysis was observed at 45°C, after 180min and enzyme/substrate ratio of 60 Anson unit/ Kg substrate. Under these conditions, degree of hydrolysis was 39.38 %. The antioxidant activity of protein hydrolysate was studied using DPPH radical scavenging activity, reducing power and Fe++ chelating activity. The most DPPH radical scavenging activity was 57.5%, that was obtained at 45ºC, enzyme activity of 60 Au/kg and 150min of time of hydrolysis. Highest Fe++ chelating activity (44.56%) observed at 45ºC, enzyme activity of 60 Au/kg, and hydrolysis time of 180min. The highest reducing ability of protein hydrolysate observed at 120min. Hydrolysis time which showed 67.32% reducing power compared to 100 ppm ascorbic acid (100 %).