不同地区来源开菲尔粒微生物多样性分析及发酵酸奶品质研究

Analysis of microbial diversity in Kefir granules from different sources and research of fermented yogurt quality

中文关键词:  开菲尔粒  微生物多样性  酸奶  品质分析

英文关键词:Kefir granules  microbial diversity  yogurt  quality analysis

中文摘要:

      目的 探究4种不同地区来源的开菲尔粒中的微生物多样性。方法 使用传统分离纯化、分子生物学技术、高通量测序等方法探究不同来源开菲尔粒中的微生物多样性。以8%接种量发酵4种开菲尔酸奶, 分析比较酸奶的蛋白质含量、总酸、pH及持水力, 并利用质构仪测定其质构特性。结果 种水平上, 4种地区来源的开菲尔粒共有的优势真菌为单孢哈萨克斯坦酵母(Kazachstania unispora)和马克斯克鲁维酵母(Kluyveromyces marxianus), 优势细菌为马乳酒乳杆菌(Lactobacillus kefiranofaciens)、开菲尔乳杆菌(Lactobacillus kefir); 真菌的操作分类单元(operational taxonomic units, OTUs)共35个, 其中4种开菲尔粒共有OTUs数为3个; 细菌的OTUs共12个, 其中4种开菲尔粒共有细菌OTUs数为3个; 德国发酵酸奶胶黏性好但酸度过高; 中国的发酵酸奶咀嚼性高但持水力较差; 俄罗斯的发酵酸奶持水力及大部分质构特性优良, 但咀嚼性较差; 美国的发酵乳蛋白质含量最高但质构特性较差。结论 本研究揭示了不同来源开菲尔粒的微生物多样性及其对酸奶品质的显著影响。中国开菲尔粒以马克斯克鲁维酵母为优势菌种, 赋予酸奶独特的风味和较高咀嚼性; 德国样品则表现出优异的胶黏性, 但酸度过高需工艺优化。微生物群落差异直接导致了酸奶理化与质构特性的区域性特征, 为开菲尔菌剂的定向筛选提供了理论依据。

英文摘要:

      Objective To explore the microbial diversity among 4 kinds of Kefir granules from different regions. Methods Traditional separation and purification, molecular biology technology, high-throughput sequencing and other methods were used to explore the microbial diversity in Kefir granules from different sources. The 4 kinds of Kefir yogurt were fermented with 8% inoculum. The protein content, total acid, pH and water holding capacity of yogurt were analyzed and compared, and their texture characteristics were determined by texture analyzer. Results At the species level, the dominant fungi shared by Kefir granules from 4 kinds of regions were Kazachstania unispora and Kluyveromyces marxianus, and the dominant bacteria were Lactobacillus kefiranofaciens and Lactobacillus kefir. There were a total of 35 operational taxonomic units (OTUs) in fungi, among which 4 kinds of Kefir granules had a total of 3 OTUs. There were 12 bacterial OTUs in total, of which 3 were common to the 4 kinds of Kefir granules. German fermented yogurt had good viscosity but with high acidity, and Chinese fermented yogurt had high chewiness but with poor water holding capacity. Russian fermented yoghurt had good water holding capacity and most texture properties, but its chewiness was poor. Fermented milk in the United States had the highest protein content, but poor texture properties. Conclusion This study reveals the microbial diversity of Kefir granules from different sources and its significant impact on the quality of yogurt. Chinese Kefir granules, with Kluyveromyces maximus as the dominant strain, endow yogurt with unique flavor and high chewiness. German samples show excellent stickiness, but their too high acidity required process optimization. The differences in microbial communities directly lead to regional characteristics in the physicochemical and textural properties of yogurt, providing a theoretical basis for the targeted screening of Kefir agents.