Changes in gel forming ability and cross-linking ability of myosin heavy chain of Alaska pollack surimi denatured by heat treatment.

Abstract

Alaska pollack surimi having different Ca-ATPase activities and salt solubilities were reconstitued by mixing in various ratios of native and heated (at 100°C for 90min) surimi, and chopped in a silent cutter with 3% salt, and then incubated at 10°C or 20°C to induce setting. Changes in gel strength and myosin heavy chain were investigated as a function of time for setting.The native surimi showing high Ca-ATPase activity (280μmol Pi/min•10g surimi) as well as high salt solubility formed elastic gel and highly cross-linked myosin heavy chains on setting of the paste. On the other hand, the paste from wholly denatured surimi by heat treatment could form unelastic gel and showed no change in myosin heavy chain. The pastes from reconstituted surimi from the above two having lower Ca-ATPase activity than 100μmol Pi/min•10g surimi hardly formed elastic gels neverthless cross-linked myosin heavy chain was produced to some extent. In the cases, Ca-ATPase activity was above that level, formation of elastic gel was closely correlated with production of cross-linked myosin heavy chains.These results suggested that formation of a gel by setting at both temperatures of 10°C and 20°C required for the production of some framework made up of cross-linked myosin heavy chains above the gelation limit.