Changes in the Physicochemical Properties of Spent-hen Meat during Cold and Frozen Storage

산란노계육(産卵老鷄肉)의 냉장 및 동결저장 중 물리화학적 특성 변화

This study was carried out to investigate the changes in the pH, extractability of protein, ATPase activity of myofibrillar protein, myofibrillar fragmentation, freezing loss and drip loss during storage at $4^{\circ}C$ and $-20^{\circ}C$ in breast and leg muscle of spent-hen meat. pH values ill pectoral and leg muscle were lowest ell tile 1st day and 1st week during cold and frozen storage, respectively. The extractabilities of myofibrillar proteins were increased graduall during cold storage and were highest on the 1st week during frozen storage, The $Mg^{2+}-ATPase$ activities of myofibrillar proteins were highest on the 1st day and 1st week during cold and frozen storage, respectively. The myofibrillar fragmentations were greatly changed on the 1st day during cold storage and 1st week during frozen storage. Freezing losses and drip losses were increased gradually during frozen storage. pH values in breast muscle were lower than those of leg muscle, and the extractabilities, $Mg^{2+}-ATPase$ activities, fragmentations of myofibrillar proteins, and drip losses in breast muscle were higher than those of leg muscle during storage, but the patterns of the changes in both muscles were similar during storage.

산란노계육(産卵老鷄肉)(Arbor Acres, 72주령(週齡))의 가슴근육과 다리근육을 냉장 및 동결저장하면서 pH, 단백질의 추출성, 근원섬유단백질의 ATPase 활성, 소편화, 냉동감량 및 드립량의 변화를 비교하였다. 가슴근육과 다리근육의 pH는 각각 냉장 1일 및 동결저장 1주에 가장 낮았다. 근원섬유단백질의 추출성은 냉장기간이 경과하면서 점차 증가하였으며, 동결저장에서는 1주에 가장 높은 수준을 보였다. 근원섬유단백질의 $Mg^{2+}-ATPase$활성은 냉장 1일 및 동결저장 1주에 각각 높게 나타났다. 근원섬유의 소편화 정도는 냉장 1일 및 동결저장 1주에 크게 변화하였으며 냉동감량과 드립량은 동결저장 기간이 경과하면서 점차 많아졌다. 냉장 및 동결저장 중 가슴근육은 다리근육에 비하여 pH가 낮았고, 근원섬유단백질의 추출성, $Mg^{2+}-ATPase$활성, 드립량 및 소편화 정도가 높았으나 저장기간 중 변화되는 양상은 비슷하였다.