Summary:
Fish protein isolates (FPI) were extracted from haddock (Melanogrammus aeglefinus) cut-offs using the pH-shift method. Flow behavior and some functional properties of FPI containing 19% protein (pH 6.4) and different amounts of salt, sucrose and also polyphosphate stored 12 weeks at -18 ° C were studied. Additives influenced viscosity, but not flow behavior. Adding salt and sucrose increased water holding capacity (WHC), but significantly decreased viscosity (Brabender Unit) and whiteness. Using polyphosphate and sucrose did not affect WHC, and whiteness of FPI but it decreased viscosity. Different amounts of additives and frozen storage time changed functional attributes of FPI significantly. The results suggest
that the isolated proteins obtained through the pH-shift also need to be preserved against denaturation during frozen storage like surimi.