Effects of Condition Enzymatic Hydrolysis on Degrees of Hydrolysis and Antioxidant Activity of Head Protein of Bighead (Aristichthys nobilis)

Background and Objectives: Enzymatic hydrolysis is an effective practical technology that recovers valuable proteins from far-less farmed fish without losing their nutritional characteristics. Enzymatic hydrolysis of protein sources such as aquatic animals is a type of protein recycling. In the present study, effects of temperature, time and concentration of papain enzyme on hydrolysis degree and antioxidant activity of the hydrolyzed protein of carp (Aristichthys nobilis) have been investigated.  Materials & Methods: Hydrolyzed protein of bighead carp heads was prepared using papain enzyme (1:100) for 4 h. Variables to achieve the best hydrolysis conditions included temperatures of 35, 37, 39 and 42 °C, hydrolysis times of 30, 48, 72 and 96 min and enzyme concentrations of 2, 4, 5 and 10%. Results: Results of this study showed that hydrolyzed protein at 42 °C, 5% enzyme concentration and 72 min included the highest antioxidant activity (0.44% ±45.25). The highest hydrolysis degree reported at 42 °C, 96 min and 10% enzyme concentration was 0.90% ±27.36. Conclusion: Based on the results, it can be concluded that the disposable components of bigheads, including heads, can be used as sources of natural antioxidants.