- 期刊
- OpenAccess
Changes in Toughness, Leaching Loss and Myofibril Fragmentation of Pacific Saury (Cololabis saira) Muscle during Iced Storage
冰藏期間秋刀魚肉之硬度、水漂流失及肌原纖維斷片化之變化
摘要
為瞭解秋刀魚在冰藏期間肌原纖維斷片化對魚肉硬度、水漂流失率的影響，將冷凍全魚解凍後進行10天的冰藏實驗。魚片的硬度在冰藏前5天期間逐漸下降，而後維持定值；將普通肉之碎肉以鹼水漂脫色時，冰藏5天後的魚肉乾物的流失率為77%，而冰藏7天者增至93%。肌原纖維在冰藏期間明顯的斷片化，依肌原纖維斷片的肌節數可分三群：1~4節的斷片為A群，5~10節的斷片為B群，10節以上為C群；將各群斷片的數目除以三群總數即為肌原纖維斷片化的比率。由冰藏5天的魚肉所得A群肌原纖維斷片的數目的比率為81%，而冰藏7天者則增至92%。結果顯示，A群與C群的平均值與水漂流失率具高相關性，而B群與C群的平均值與魚肉硬度亦有正相關性（r^2分別為0.950與0.852）。SDS電泳圖型顯示，在冰藏10天期間魚肉的肌漿蛋白與肌原纖維蛋白無明顯變化，鹼可溶性蛋白的圖型雖為相近，但其濃度則隨貯藏時間延長而增大。本研究的結果顯示，導致秋刀魚碎肉的高水漂流失率的主因為肌原纖維在冰藏中的快速斷片化而非蛋白質的變性。
並列摘要
The effect of myofibril fragmentation on the changes in toughness and leaching loss of Pacific saury (Cololabis saira) muscle was studied. Frozen round fish was thawed and provided to the experiment of 10-days ice-storage. The toughness of fillet decreased during the initial 5-days storage and it maintained the constant thereafter. As the ordinary muscle of fish was minced and washed conventionally with alkali medium to lighten the color, the dry mass lost was 77% when fish were stored for 5 days. It would increase to 93% as prolonging storage of samples to 7 days. Myofibrils fragmentized quickly during the iced storage. According to the numbers of sarcomere in one fragment, the myofibril fragmentations were classified to three groups: 1-4 sarcomeres (group A), 5-10 sarcomeres (group B), and above 10 sarcomeres (group C). The proportion of numbers of A group to the sum of 3 groups (fragmentation ratio) extracted from 5-days iced fish was 81%, and it became 92% from those of 7-days storage fish. The changes in the means of numbers of Group A+C or Group B+C showed high correlation with the changes in leaching loss and toughness of flesh respectively (r^2 0.950, 0.852,). SDS-polyacrylamide gel electrophoresis patterns showed no obvious changes in water-soluble sarcoplasmic and salt-soluble myofibrillar proteins. Though alkali-soluble protein showed similar patterns during the storage, the bands showed the increasing intensity with the prolonging storage period. It suggested that the high leaching loss of Pacific saury minced muscle during the iced storage was mainly resulted from the fragmentation of myofibril but not the denaturation of protein.