Functional and physicochemical properties of protein from giant squid (Dosidicus gigas) extracted using foam-aided pH-shift processing

Abstract

Jumbo squid (Dosidicus gigas) is a commercially valuable mollusk in Mexico; (à% of its body is edible. Despite the high protein content (∼ (%) and low cholesterol content of this species, its high proteolytic activity (microbial and endogenous enzymes) induces protein degradation and consequent reduction in functional properties from a structural viewpoint. Gelation capacity (texture profile of the gels obtained), solubility, water holding capacity, foaming capacity, emulsification capacity, and emulsion stability were evaluated in protein con- centrates obtained by foam-aided pH-shift processing: (A) myofibrillar protein extraction with distilled water and no pH-shifting; (B) alkaline solubilization and isoelectric precipitation; (C) acidic solubilization and isoelectric precipita- tion; and (D) process A and isoelectric precipitation. Process B showed superior gelation capacity, D had high emulsion stability across a wide range of pH val- ues ().à–(.à) and C lower plate counts of aerobic mesophilic. Therefore, all three alternative extraction processes showed techno-functional advantages.