10. マイワシ筋肉タンパク質の凍結変性(セミナー「食品における低温の利用」)

概要

論文の詳細を見る
Sardines are underutilized, although they account for the largest part of the fish catch in Japan. They are mostly processed into fish meal and oil. One problem limiting their effective utilization may be the rapid loss of protein quality during storage, since the muscle pH decreases quickly after death, easily reaching the ultimate pH of 6 or lower. During frozen storage at -20℃, myofibrillar Ca^<2+>-ATPase of sardine ordinary muscle lost half of the original activity within 2 days of storage, while the activity remained quite stable thereafter. The ordinary muscle myofibrils displayed a remaining Ca^<2+>-ATPase activity maximum at pH 7.5 and little activity below pH 6.5, when suspended in buffers of various pH values and stored at -20℃ for 2 days. Freeze denaturation of ordinary muscle myofibrils was more obviously observed in the acidic pH region, when remaining Mg^<2+>-and K^+ (EDTA)-ATPase activities were measured under the same conditions described above. Extremely low Mg^<2+>-ATPase activity was demonstrated even at pH 7.0. Compared with ATPase activities, there were much less changes in solubility in 0.5M KCl at any pH with sardine ordinary myofibrils. Sardine dark muscle, which accounts for about 30% of the total muscle, exhibited similar changes to ordinary muscle in myofibrillar ATPase activities and solubility during frozen storage at -20℃ for 2 days.
低温生物工学会の論文
1991-10-20