Covalent Cross‐linking Effects on Thermo‐Rheological Profiles of Fish Protein Gels

The extent of covalent cross‐linking in surimi sols by transglutaminase was modified by addition of either EDTA (inhibition by calcium sequestering), variation of preincubation time at 25°C to allow action of endogenous transglutaminase, or by addition of a microbial transglutaminase. Gels were cooked following preincubation to fix the effects of the cross‐linking reaction. Torsion, dynamic (small strain) test and stress relaxation measurements were made on the gels over a range of temperatures. Gels preincubated with EDTA had similar rheological response to temperature as gels cooked without preincubation. The stress relaxation and thermo‐rheological profiles of gels with increased covalent cross‐linking (induced by added or endogenous transglutaminase) were increasingly rubber elastic in their behavior.