原料驼乳在冷藏过程中的微生物群落演替是一个复杂而显著的过程,对驼乳的品质产生重要影响。该文对原料乳冷藏过程的理化性质及微观特征进行研究,比较4 ℃冷藏6 d原料乳的微观结构和蛋白结构的差异,探讨冷藏原料乳的变质规律。结果表明,随冷藏时间的延长,原料乳中主要理化性质(脂肪、蛋白质、乳糖)呈现动态变化,pH总体上均呈下降趋势,主要微生物(菌落总数、嗜冷菌数、大肠杆菌数、乳酸菌数)均显著增加。冷藏3 d后关键酶(脂肪酶及蛋白酶)酶活性均呈下降趋势;此外,基于傅里叶红外光谱分析不同冷藏处理的原料乳结果显示,随冷藏时间的延长,原料驼乳中脂肪、蛋白质和乳糖在3 d后峰值发生偏移。因此,冷藏第3天为原料驼乳品质控制关键阶段。
The microbial community succession of raw camel milk during cold storage is a complex and significant process, which has an important impact on the quality of camel milk.In this paper, the physical and chemical properties and microscopic characteristics of raw milk during cold storage were studied.The differences in microstructure and protein structure of raw milk stored at 4 ℃ for 6 days were compared, and the deterioration law of raw milk during cold storage was discussed.Results showed that with the extension of cold storage time, the main physical and chemical properties (fat, protein, lactose) in raw milk showed dynamic changes, and the pH generally showed a downward trend.The main microorganisms (total number of colonies, number of psychrophilic bacteria, number of Escherichia coli, number of lactic acid bacteria) increased significantly.After 3 days of cold storage, the activity of key enzymes (lipase and protease) decreased.In addition, based on Fourier transform infrared spectroscopy, the results of raw milk with different cold storage treatments showed that with the extension of cold storage time, the peaks of fat, protein and lactose in raw camel milk shifted after 3 days.Therefore, the third day of cold storage is the key stage of quality control of raw camel milk.
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