Electron Microscopic Study on the Processes of Preparation of Kamaboko

Abstract

Changes of fine structures of fish muscle matters along the kamaboko preparation process were examined under electron microscope. In the minced meat (nama surimi), nearly intact myofibrillar structures were seen. The cross sections showed a hexagonal arrangement with six actin filaments surrounding each myosin filament. In the minced meat adjusted to 75-78% moisture, myofibrillar structures without any appreciable M-lines were found, while bundles of irregularly arranged filaments were observed. When the minced meat is ground with NaCl, disintegration of the myofibrillar structures was found to proceed with the length of grinding time. In the meat paste obtained by grinding the minced meat with NaCl for 15 minutes, only filaments of 7nm in diameter were observed, which was assigned as actomyosin filaments, based on its cross section structure's similar to that of actomyosin. There was a difference in fine structures between the kamabokos which were cooked with and without setting treatment. Dispersion profiles of protein were more uniform in the former than in the latter. In low protein concentration portions, network structures of single and bundled filaments were found regardless of setting treatment applied. However, filaments of setting treated kamabokos were thicker than those of non-setting kamabokos.