茶基底中微生物菌相构成分析及其对现制奶茶中菌落数量的影响

Analysis of microbial bacterial phase composition in tea base and its effect on the number of colonies in freshly-made milk tea

中文关键词:  茶基底  菌相构成  奶茶基底  微生物

英文关键词:tea base  microflora composition  milk tea base  microorganism

中文摘要:

      目的 探究茶基底菌相构成及其对制成的奶茶基底微生物的影响，为茶基底及奶茶基底的微生物控制提供理论参考。方法 通过扩增子测序技术对茶基底微生物组成分析，按照国标方法GB 4789.2—2022《食品安全国家标准 食品微生物学检验菌落总数测定》、GB 4789.15—2016《食品安全国家标准 食品微生物学检验霉菌和酵母计数》、GB 4789.3—2016《食品安全国家标准 食品微生物学检验大肠菌群计数》第一法-大肠菌群 MPN计数法测定茶基底及制成的奶茶基底中霉菌、酵母菌、大肠菌群和菌落总数的含量。结果 25个茶基底的霉菌、酵母菌、大肠菌群和菌落总数的范围分别为小于10~1.0×103 CFU/g、小于10~2.0×103 CFU/g、小于3.0~大于1.1×103 MPN/g和小于10~9.3×104 CFU/g。6类典型的茶基底样品微生物门水平优势细菌为变形菌门（Proteobacteria），丰度为77.29%，优势真菌为子囊菌门（Ascomycota），丰度为85.38%，属水平优势细菌为鞘氨醇单胞菌属（Sphingomonas），丰度占比60.57%，优势真菌属为青霉属（Penicillium），占比21.5%。选取3个不同微生物梯度水平的红茶基底样品制成奶茶基底，在25℃条件下放置6.0 h，结果显示菌落总数呈增长趋势，而霉菌、酵母菌、大肠菌群的含量均未检出。结论 茶基底中的微生物尤其是菌落总数对其制成的奶茶基底菌落总数相关性较高，热奶茶的高温制备过程可有效抑制茶基底中霉菌、酵母菌、大肠菌群的生长。

英文摘要:

      Objective To investigate the microflora composition of tea base and its influence on milk tea base microorganisms, and provide theoretical reference for the microbial control of tea base and milk tea base. Methods The microbial composition of the tea base was analyzed by amplicon sequencing technology, according to the national standard methods GB 4789.2-2022 National Standard for Food Safety Food Microbiology Test for the Determination of the Total Number of Bacterial Colony, GB 4789.15-2016 National Standard for Food Safety Food Microbiology Test for the Enumeration of Moulds and Yeasts, GB 4789.3-2016 “National Standard for Food Safety Food Microbiology Test for Coliform Count” First Method - Coliform MPN counting method for the determination of molds, yeasts, coliforms and total colony counts in the tea base and the freshly-made milk tea. Results The total number of molds, yeasts, coliforms and colonies in 25 tea bases were <10～1.0×103 CFU/g, <10～2.0×103 CFU/g, <3.0～>1.1×103 MPN/g and <10～9.3×104 CFU/g, respectively. Among the six typical tea base samples, the dominant bacteria was Proteobacteria, with an abundance of 77.29%, and the dominant fungi was Ascomycota, with an abundance of 85.38%. Sphingomonas (60.57%) was the dominant bacterium at genus level, and Penicillium (21.5%) was the dominant fungus. Three black tea base samples with different microbial gradients were selected to make milk tea base and placed at 25℃ for 6 h. The results showed that the total number of colonies showed an increasing trend, while the contents of mold, yeast and coliform were not detected. Conclusion The microorganisms in the tea base, especially the total number of colonies, had a high correlation with the total number of colonies in the milk tea base. The high temperature preparation process of hot milk tea can effectively inhibit the growth of mold, yeast and coliform in the tea base.