Abstract:To enhance the quality stability of braised beef during frozen storage，the effects of three pre-cooling methods on its quality were investigated. The methods included -80 ℃ liquid nitrogen spray freezing （LNF group），-80 ℃ refrigerator freezing （RF group），and -20 ℃ refrigerator freezing （MF group）. The evaluation of their effects was based on measurements of freezing time，water-holding capacity，color，hardness，myofibril fragmentation index （MFI），volatile flavor compounds，and microstructure. The results showed that the time for the LNF group to reach the final freezing temperature （-10 ℃） was shortened by 40 min and 204 min compared with the RF and MF groups，respectively，demonstrating an efficient rapid pre-cooling capability. The centrifugal water loss rate and thawing loss rate of the LNF group were 10.37% and 5.28%，respectively，with no significant difference from the RF and MF groups （P＞0.05），but the color stability was better and closer to that of fresh braised beef. Furthermore，the hardness of the LNF group （916.45 g） was significantly lower than that of the RF group （1 573.82 g） and the MF group （1 872.93 g） （P＜0.05），while its MFI value （81.27） was significantly higher than those of the other groups （P＜0.05），with better retention of flavor characteristics. It was observed by microstructural analysis that the muscle tissue structure in the LNF group was more uniform and compact，and the ice crystals formed were smaller and more evenly distributed. In conclusion，the -80 ℃liquid nitrogen pre-cooling technology can significantly improve the texture characteristics，enhance the color stability，and improve the flavor retention of braised beef.