南山牧场生鲜牛乳理化指标与微生物多样性对比分析

Comparative Analysis of Physical and Chemical Indexes and Microbial Diversity of Fresh Cow Milk in Nanshan Pasture

为了解南方山区牧场牛乳的特性,改善山区牧场地区原料乳的品质以及合理开发利用提供理论依据,本文比较分析了湖南南山牧场与城郊牧场生鲜牛乳的理化指标(常规成分、矿物质元素、氨基酸组成、挥发性成分)及微生物多样性。结果表明:南山牧场牛乳与城郊牧场牛乳各个常规营养成分呈明显差异,其中,南山牧场牛乳游离脂肪酸含量高达5.34 mg/kg,且铁与锌的含量分别为5.200和6.390 mg/L,明显高于城郊牧场牛乳;南山牧场牛乳中氨基酸总量为3.102 g/100 g,低于城郊牧场牛乳;城郊牧场牛乳中共检出13种挥发性物质,而南山牧场牛乳挥发性成分测定共检出11种物质,低于城郊牧场牛乳。微生物多样性测定发现两个牧场之间细菌类群的组成比例明显不同,城郊牧场两种样品细菌类群多样性丰富,组成大致相同,占优势丰度的为肠球菌,南山牧场牛乳中不动杆菌属为优势菌群。综合分析表明,同一品种的牛乳受地理环境因素影响大,不同牧场之间牛乳的常规成分、矿物质及氨基酸含量都有明显差异;微生物多样性受环境因素影响较显著。

In order to understand the characteristics of cow milk in southern mountain pastures,improve the quality of raw milk in mountain pastures,and provide a theoretical basis for rational development and utilization,this article compared and analyzed the physical and chemical indicators(conventional ingredients,mineral elements,amino acid composition,volatile components)and microbial diversity of fresh milk in Nanshan Ranch and Suburb Ranch in Hunan.The results showed that:Nanshan Ranch cow milk and Chengjiao pasture cow milk had significant differences in their conventional nutrients.Among them,the milk in Nanshan Ranch content of free fatty acids was as high as 5.34 mg/kg,and the contents of iron and zinc were 5.200 and 6.390 mg/L,which were significantly higher than Milk in the suburban pastures;the total amino acid content in the milk in Nanshan pastures was 3.102 g/100 g,which was lower than that in the milks in the suburban pastures;a total of 13 volatile substances were detected in the milk in the suburban pastures,and a total of 11 substances were detected in the determination of volatile components in the milk in the Nanshan pastures Lower than cow milk in suburban pastures.The determination of microbial diversity found that the composition ratio of the bacterial groups between the two pastures was significantly different.The bacterial samples of the two suburban pastures were rich in diversity and the composition was roughly the same,the dominant abundance was Enterococcus,and Acinetobacter in the milk of Nanshan pasture for the dominant flora.Comprehensive analysis showed that the milk of the same breed was greatly affected by geographical environmental factors,and the conventional ingredients,minerals and amino acid content of milk in different pastures were significantly different;the microbial diversity was significantly affected by environmental factors.