In modori gel,the disappearance of MHC with the coincidental increase in trichloroacetic acid(TCA) soluble peptide content (datanotshown) suggested the degradation of MHC
during incubation at 60 1C. The degradation of MHC in the modori gel was coincidental with the decreased breaking force (Fig. 1A). High degradation of MHC was reported in surimi gel from dark-fleshed fish including mackerel. Alkaline proteases have been reported to contribute to the
protein degradation in surimi gels from dark flesh fish such as sardine and mackerel. Modori gel
added with80 mmol/kg ZnSO4 or ZnCl2 also had the high MHC band intensity,suggesting that Zn2+ might inactivate both proteases and transglutaminase in modori gel.Thus,Zn2+ concentration determined both protein polymerisation and degradation in surimi gel from yellows tripe trevally.