Effects of pre-freezing methods and storage temperatures on the qualities of crucian carp (Carassius auratus var. pengze) during frozen storage

摘要

Pengze crucian carp was pre-frozen by liquid nitrogen and freezer, and then stored at−20/−40°C and −20°C, respectively, for 15-60 days. Effects of pre-freezing methodsand storage temperatures on the qualities of fish were investigated. The pH showeda “V” trend. The soluble myofibrillar protein content, hardness, springiness, cohesiveness,gumminess, chewiness, and resilience decreased. Thiobarbituric acid value,total volatile basic-nitrogen value, thawing and cooking loss rates increased with theextending of storage period. LF-NMR analysis indicated that the water-protein connectionbecame less tight. Moreover the qualities decline degrees were higher forfreezer pre-frozen than liquid nitrogen pre-frozen, and higher for −20°C storage than−40°C storage. Accordingly, compared with conventional freezer pre-freezing andstorage, liquid nitrogen pre-freezing and low temperature storage could inhibit theoxidation and degradation, and keep better water holding and textural properties ofmuscle. The present study showed a great potential application in aquatic productsprocessing industry.