Functional properties and dynamic rheology of protein isolates extracted from male and female common carp (Cyprinus carpio) muscle subjected to pH-shifting method

The present study showed the physicochemical and functional properties of protein isolates prepared from male and female common carp (Cyprinus carpio) muscle using pH-shift method. The alkali (BPIs) and acid (APIs) protein isolates showed higher protein content than raw muscle. The decline in fat and ash content due to the removal of connective tissue during separation process was observed. The color properties of isolates varied significantly between gender as well as processing methods which could be related to total pigment content. The processing methods and gender differences resulted a significant variation in water absorption capacity, emulsifying activity index, emulsifying stability index, foaming stability, storage modulus, loss modulus, and G(reinforcement). The SDS-PAGE analysis showed the presence of different molecular weight polypeptides influencing functional and rheological properties of protein isolates from both genders. The present study overall depicted rheological and functional properties of BPIs and APIs from male were better than that of female. Practical applications Common carp being an exotic fish is cultured throughout India, especially in northern region. The present study entails comparative analysis of physicochemical, functional, and rheological properties of FPIs (BPIs and APIs) by pH-shift method from both genders. The results from present study suggested that understanding the functionality of protein isolates prepared from different genders and processing methods can enhance their application as ingredients in food industry to make them more suitable for human consumption.