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.