Changes in structural properties of porcine myofibrillar protein induced by frozen storage

Changes in structure property of myofibrillar protein from porcine longissimus dorsi were monitored during 12 months of storage at -5, -18, -26, -35 and -70 degrees C. With the extended frozen time at the same temperature, Ca2+-ATPase activity, K+-ATPase activity, total sulfhydryl content reactive sulfhydryl content decreased (P < 0.05), surface hydrophobicity (S-0-NAS) increased (P < 0.05). Meanwhile, stucture of myofibrillar protein was more susceptible to high frozen storage temperature than low frozen storage temperature. There was markedly loss in band intensity of myosin heavy chain, actin, paramyosin, troponin, and propomyosin from frozen meat within frozen storage.