Effect of Different Degrees of Deep Freezing on the Quality of Snowflake Beef during Storage

In order to elucidate whether deep freezing could maintain the quality of snowflake beef, three different deep freezing temperatures (-18 °C, -40 °C, and -60 °C) were used in order to evaluate the changes in tissue structures, quality characteristics and spoilage indexes, and their comparative effects on the quality of snowflake beef. Compared to samples frozen at -18 °C, those stored at -40 °C and -60 °C took a shorter time to exceed the maximum ice crystallization zone (significantly reduced by 2-6 h). In terms of short-term storage, samples frozen at -40 °C and -60 °C had better tissue structure and lower drip loss rate than those frozen at -18 °C; significant differences between groups in drip loss were observed between -18 °C and -60 °C. Moreover, a better bright red color and lower shear force were maintained at -40 °C and -60 °C, with significant differences in shear force between the -18 °C group and the other two groups on day 60. Although there were significant effects on the inhibition of lipid and protein oxidation at -40 °C and -60 °C; no significant variation was observed between these two groups throughout storage. A similar phenomenon was found in flavor, with 1-pentanol identified as an important potential indicator of flavor change in snowflake beef during storage. This study demonstrated that -40 °C and -60 °C had favorable impacts on the quality maintenance of snowflake beef compared to -18 °C. These findings provide a theoretical basis for effective stability of snowflake beef quality during frozen storage.