普洱茶优势菌株黑曲霉的分离及其功能和 安全性研究

Research on identification, function and safety of Aspergillus Niger, a pre-ponderant fungus during the fermentative process of Pu'er tea

中文关键词:  普洱茶  黑曲霉  分离  鉴定  赭曲霉毒素  安全性

英文关键词:Pu'er tea  Aspergillus niger  separation  identification  ochratoxin  safety

中文摘要:

      目的 了解黑曲霉在普洱茶渥堆发酵中的功能和安全性。方法 利用平板涂布法从普洱茶中分离、纯化得优势菌株S6, 通过分子鉴定为黑曲霉; 将黑曲霉按照悬浮液107个/mL, 接种于潮水量35%的云南大叶种晒青毛茶, 30 ℃、发酵25 d制备得发酵茶样, 按照GB 22111-2008进行感官、理化和安全性评价。结果 优势菌株黑曲霉纯种发酵的茶样香气浓纯、汤色黑褐色、滋味较平和, 达到三级茶叶标准要求, 对比对照茶样, 具有茶褐素、红度和黄度等变化较为深刻, 且赭曲霉毒素的含量为3.80 μg/kg, 低于国内外限量。结论 优势菌株黑曲霉可以作为发酵用菌种, 适于普洱茶的渥堆发酵, 发酵样的安全性高。

英文摘要:

      Objective To understand the function and safety of Aspergillus niger during the fermentative process of Pu'er tea. Methods The preponderant fungus S6 was separated and purified from Pu'er tea in the plate method, and it was Aspergillus niger through the use of molecular identification. Then Aspergillus niger, following suspension 107/mL, was inoculated on the sun-dried green tea with 35% water, cultured for 25 d with 30 ℃, then the sensory, security, physical and chemical evaluations of fermented sample were operated according to GB 22111-2008. Results The research results showed that compared with CK, the content of the tea sample in fermentation of Aspergillus niger was the abrownins, redness and brightness. It was achieved the third standard and was changed significantly in the fermented sample with sweet aroma, black brown tang, velvety flavor, and the content of ochratoxin was 3.80 μg/kg under the limitation of home and abroad. Conclusion Aspergillus niger is one of preponderant fungus during the fermentative process of Pu'er tea, and plays a very important role to the formation of Pu'er tea quality with high safety.