Effect of gluconate on heat-induced gelation of myosin from red sea bream

Abstract

The aim of this study was to clarify the eŠect of gluconate on heat-induced gelation of myosin. Myosin puried from ordinary muscle of red sea bream Pagrus major was incubated at 80°C and then cooled to make heat-induced gel. The breaking strength of the gel formed with gluconate was 4 6 fold larger than that formed with chloride salt. Scanning microscopy showed that the gel with gluconate had aˆner and more regular network structure.Gluconate strongly suppressed the thermal denaturation of myosin, but the eŠect of the suppression was similar to that in the case of sorbitol. On the other hand, gluconate heightened the gel-melting temperature more eŠectively than sorbitol. The partial speciˆc volume of myosin in sodium gluconate solution was 0.65 cm 3 /g, which was much smaller than that in sodium chloride solution (0.71 cm 3 /g). Furthermore, the values of the adiabatic compressibility of myosin in chloride salt solution were positive, while those in gluconate solution were negative, indicating that gluconate remarkably increased the amount of hydration of myosin. These results suggested that gluconate strengthened intermolecular hydrophobic interactions by changing the water structure around myosin molecules.