マサバ普通肉中のイノシン酸分解に及ぼす血合肉の影響

Abstract

It has been shown that inosinic acid (IMP) hydrolyzing enzyme has high activity at pH 6.0 in the dark muscle of common mackerel Scomber japonicas and is easily soluble in water. This suggests the possibility that the enzyme in the dark muscle may affect the degradation of IMP in the white muscle of common mackerel. It was found that the IMP degradation in the white muscle homogenate was accelerated by mixing the dark muscle homogenate during a 4 days period of storage in ice. A similar phenomenon was also clearly observed when the minced white muscle was mixed with 10% of minced dark muscle during a 7 days period of storage in ice. After 8 days of storage in ice, when the contents of ATP-related compounds in the white muscle of common mackerel were determined in the fillets with and without the dark muscle, it was observed that IMP was slightly higher and inosine was slightly lower in the fillet without the dark muscle than in the fillet with the dark muscle. These results strongly indicate that the enzyme of the dark muscle affected the degradation of IMP in the white muscle of common mackerel.