Effects of Microwave Radiation and Water Bath Heating on the Physicochemical Properties of Actomyosin from Silver Carp (Hypophthalmichthys molitrix)during Setting

Changes in the physical and chemical characteristics of actomyosin, isolated from silver carp (Hypophthalmichthys molitrix), induced by heating in a water bath and microwave oven were investigated. Ca2+-ATPase showed a heating-time-dependent decrease in activity, suggesting denaturation of myosin and dissociation of the actomyosin complex. The decrease in actomyosin solubility indicates the formation of protein aggregates. In addition, reactive sulfhydryl (R-SH) groups increased and total SH (T-SH) groups decreased with heating, indicating the formation of disulfide bonds through SH oxidation or disulfide interchanges. The differences of surface hydrophobicity (S0) showed microwave heating has an inhibitory effect on protein conformation changes. Fourier transform infrared confirmed the conformational changes of silver carp actomyosin. This study demonstrated that microwave heating can effectively depressed actomyosin structural changes during heating and provided useful information for surimi production. Practical Applications At present, there is lot of research about heat-induced gel from fish protein, but the way they used are traditional water bath or ohmic heating. Though reports of microwave heating on structure and the characteristics of fish protein are few, it is important for surimi gelation and microwave sterilization. We supposed microwave heating could influence the structure of fish protein and improve the quality of surimi. A preliminary study of microwave heating on actomyosin not only can enrich theory of heated induced protein gel also has important scientific value.