COVALENT CROSS-LINKING EFFECTS ON THERMORHEOLOGICAL PROFILES OF FISH-PROTEIN GELS

The extent of covalent cross-linking in surimi sols by transglutaminas e was modified by addition of either EDTA (inhibition by calcium seque stering), variation of preincubation time at 25 degrees C to allow act ion of endogenous transglutaminase, or by addition of a microbial tran sglutaminase. Gels were cooked following preincubation to fix the effe cts of the cross-linking reaction. Torsion, dynamic (small strain) tes t and stress relaxation measurements were made on the gels over a rang e of temperatures. Gels preincubated with EDTA had similar rheological response to temperature as gels cooked without preincubation. The str ess relaxation and thermo-rheological profiles of gels with increased covalent cross-linking (induced by added or endogenous transglutaminas e) were increasingly rubber elastic in their behavior.