Myosin Denaturation Study for the Quality Evaluation of Fish Muscle-based Products

Abstract

Myosin is the major protein in fish muscle and determines the quality of the muscle. Fish myosin is typically unstable, especially myosin from cold-water fish species. Accordingly, an understanding of species-specific myosin denaturation is important for evaluating the quality of fish muscle. The myosin molecule consists of a head and tail portion and thus the denaturation of these two regions was analyzed upon the heating and freezing of myofibrils (Mf). Moreover, preferential actin denaturation determines myosin denaturation in Mf upon treatment with high concentrations of salt or by freezing. The indices for detecting myosin and actin denaturation in Mf were successfully applied to evaluate the quality of Bluefin tuna samples and frozen surimi. In addition, the unique myosin denaturation observed with squid Mf is discussed.