Quality stability of bovine colostrum: Unraveling the effects of storage at different freezing temperatures

Bovine colostrum, rich in immunoactive proteins and nutrients, deteriorates rapidly under conventional refrigeration (2-4°C) within 1 d, limiting its industrial application. This study aimed to evaluate the effects of storage at different freezing temperatures (-5°C, -20°C, and -80°C) for up to 25 d on the sensory, physicochemical, and microbial characteristics of bovine colostrum and to identify a storage strategy that balances quality retention and economic feasibility. Results indicate that although -80°C provided the superior quality preservation throughout the storage period, -20°C maintained comparable overall quality for the initial 15 d. Furthermore, the decline in key flavor volatiles (e.g., acetone) and the selective enrichment and persistence of psychrotrophic genus Chryseobacterium are associated with the overall quality deterioration during storage. In conclusion, -20°C storage appears to be the optimal balance between quality retention and cost-effectiveness for industrial applications, effectively extending shelf life to 15 d with minimal quality loss and facilitating broader use in functional dairy product manufacturing.