关键词: 生羊乳；近冰点贮藏；理化特性；蛋白质结构；微生物群落

Abstract: To investigate the effect of near-freezing temperature storage on the physicochemical properties and microbial community structure of raw goat milk and to optimize its preservation process, this study conducted a 5-day storage experiment under near-freezing conditions, with storage at 4 and 10 ℃ as controls. During this period, changes in physicochemical properties, protein structure, microbial counts, and microbial community composition were monitored. The results indicated that compared with storage at 4 and 10 ℃, near-freezing temperature storage significantly delayed quality deterioration in raw goat milk and more effectively inhibited the increase in total bacterial count, coliform count, and psychrophilic bacterial count. Throughout the 5-day storage period, the total bacterial count consistently remained below the national standard limits. Additionally, near-freezing temperature storage helped maintain the stability of the secondary and tertiary structures of goat milk proteins, ensuring favorable processing characteristics. Microbial community analysis revealed that near‑freezing temperature storage better preserved the diversity and richness of the bacterial community in raw goat milk. Under this condition, Pseudomonas gradually became the dominant genus, while the proliferation of Lactococcus and Brochothrix, both of which showed a positive correlation with the acidity of raw goat milk, was significantly suppressed. Functional prediction further indicated an enhancement in the microbiologically driven metabolism of carbohydrates, amino acids, and fatty acids during low temperature storage. Near-freezing temperature storage markedly delayed the spoilage process of raw goat milk by inhibiting the proliferation and metabolic activity of core spoilage bacteria. This study provides a theoretical basis and technical support for extending the shelf life of raw goat milk, optimizing temperature parameters for cold chain logistics, and developing novel preservation technologies for raw milk.

Key words: raw goat milk; near-freezing temperature storage; physicochemical properties; protein structure; microbial community