1Ninben Co., Ltd, Kawaguchi, Saitama 333-0848, 2College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-8510, Japan
Histochemical properties of eosin-Y positive component (EPC), which was proposed as an index for judging the quality of katsuobushi, were examined in terms of immunohistochemistry using anti-actin, -myosin, -lactate dehydrogenase (LDH), and -myoglobin polyclonal antibodies or antiserum. EPC was reacted with four antibodies and the reactants were detected dominantly in the intracellular compartmentation of muscle cell in the katsuobushi manufactured from raw materials caught by pole and line (KPL) and in the intercellular space of muscle cell in the katsuobushi manufactured from raw materials caught by purse seine (KPS).
Immunohistochemical analysis with anti-laminin polyclonal antibody revealed the existence of a significant number of cells with unclear endomysium, suggesting cell disruption, in KPS in comparison with KPL.
These results suggested that EPC was mainly composed of myofibrillar and sarcoplasmic proteins such as actin, myosin, LDH and myogloblin, and that the reduction of the intracellular EPC in KPS was caused by the spillage of EPC from the intracellular compartmentation of muscle cell to the intercellular space resulting from endomysium disruption being due to unknown factors in the manufacturing process of KPS.