Valorisation of low-valued ray-finned fish (Labeobarbus nedgia) by enzymatic hydrolysis to obtain fish-discarded protein hydrolysates as functional foods

Abstract

This study investigated the valorisation of low-valued ray-finned fish (Labeobarbus nedgia) (LB) muscle into valuable protein hydrolysates using three commercial enzymes (Alcalase®, Novozym®, and Protease®). After testing different enzyme concentrations (0–3 %, v/w) and temperatures (50–70 °C), the best results, including the highest degree of hydrolysis (DH) and antioxidant activity, were achieved when using Alcalase® at 3 % (v/w) and a temperature of 60 °C. However, Novozym® was found to be more resistant to high temperatures than Alcalase®. Functional properties of freeze-dried protein hydrolysates prepared using Alcalase® and Novozym®, at an enzyme concentration of 3 % (v/w) and a temperature of 60 °C, were determined. Both hydrolysates exhibited similar solubility, water and oil holding capacity, and foaming capacity and stability. This study demonstrated that the low-valued LB muscle can be used to produce a valuable protein hydrolysate, which could be used as a functional ingredient in the food industry.