Pullulan suppresses the denaturation of myofibrillar protein of grass carp (Ctenopharyngodon idella) during frozen storage.

This study aims to investigate the effect of pullulan on the denaturation of the myofibrillar protein of grass carp (Ctenopharyngodon idella) during frozen storage at -18°C for 30days. Pullulan or commercial cryoprotectant (1g dry weight) were added to 100g of the myofibrillar protein of grass carp (C. idella), respectively, which was frozenly stored at -18°C for 30days, and the changes in the state of unfrozen of water, solubility, Ca2+-adenylpyrophosphatase (ATPase) activity, and sulfhydryl content of myofibrils were monitored during frozen storage. Pullulan addition increased unfrozen water and sulfhydryl contents in the myofibrillar protein and solubility and ATPase activity of the myofibrillar protein compared with those of the control during frozen storage at -18°C. Moreover, the cryoprotective efficiency of pullulan on the myofibrillar protein of grass carp (C. idella) was higher than that of commercial cryoprotectant.