坐りに伴うスケトウダラ肉糊中のタンパク質の塩溶解性と成分組成の変化

Abstract

Frozen surimi was chopped with 2.5% NaCl at pH 6.9 and 6.0. The salt-ground meats were then incubated at 25°C. During the setting, part of the salt-ground meat was solubilized into 0.80M NaCl solution. The content and subunit components of myofibrillar proteins in salt-soluble (S) and insoluble (P) fractions were investigated. In the early stage of setting, a large amount of myosin heavy chain (HC) and actin containing tropomyosin, together with a small amount of cross-linked myosin HC (HCn) and unidentified compo-nents (X1 and X2), constituted the S fraction from meats of both pHs. With the progress of setting, the decrease in salt-soluble protein from the meat of pH 6.0 was rather slower than that of pH 6.9. In addition, all subunit components including the large amount of myosin HC disappeared from the S fraction, and a concomitant accumulation of HCn at pH 6.9 (or HCn plus X1 at pH 6.0) together with all other components was observed in the P fraction. These results indicate that all protein components in the salt-ground meat were complexed to form the salt-insoluble protein fraction in the process of setting.