普洱茶贮藏过程中“金花”菌的鉴定及其对茶叶品质的影响

Identification of “Golden Flower” Fungi in Pu-erh Tea Storage and Effects on Tea Quality

由于仓储环境的差异,普洱茶在贮藏过程中偶尔会产生"金花"。以金花普洱茶(熟茶)为实验材料,并以同批次普通普洱茶(熟茶)为参照,对水浸出物、茶多酚、游离氨基酸、茶色素(茶黄素、茶红素、茶褐素)、咖啡碱、水溶性糖、儿茶素类等化学成分含量进行测定;采用平板划线法对"金花"菌进行分离和菌落数量测定,并结合形态观察和分子生物学方法对"金花"菌进行鉴定。结果表明:金花普洱茶(熟茶)和普通普洱茶(熟茶)在水浸出物、茶多酚、儿茶素总量、EC、EGC、茶黄素、游离氨基酸、咖啡碱含量上无显著性差异(P>0.05)。金花普洱茶(熟茶)中茶红素、水溶性总糖、没食子酸含量显著(P<0.05)高于普通普洱茶(熟茶),EGCG、茶褐素含量略低于普通普洱茶(熟茶);在普洱茶贮藏过程中分离出3株"金花"菌,分别鉴定为Aspergillus pallidofulvus(相似度99.9%)、Aspergillus sesamicola(相似度99.8%)、Penicillium manginii(相似度99.6%)。其中Aspergillus sesamicola为优势"金花"菌种,占"金花"菌群数量总量的66%。首次对普洱茶贮藏中的"金花"菌进行了鉴定,初步分析了"金花"菌对普洱茶(熟茶)品质的影响,为"金花"菌在普洱茶中的应用提供了一定的理论基础与参考价值。

Due to the difference in storage environment,Pu-erh tea will occasionally produce "Golden Flowers" in the process of storage.In this paper,Jinhua Pu-erh tea(ripened tea) is used as the experimental material,and the same batch of ordinary Pu-erh tea(ripened tea) is used as reference.Contents of chemical constituents such as water extract,tea polyphenol,free amino acid,tea pigments(theaflavins,thearubigins and theabrownins),caffeine,water-soluble sugar and catechins were determined. "Golden Flower" fungi were separated by plate scribe method and the number of colonies were determined."Golden Flower" fungi were identified based on morphological observation and molecular biological method.The results showed that Jinhua Pu-erh tea(fermented tea) and ordinary Pu-erh tea(fermented tea) had no significant(P>0.05) differences in water extract,tea polyphenols,total catechins,EC,EGC,theaflavins,free amino acids and caffeine.The content of thearubigins,watersoluble total sugar and gallic acid in Jinhua Pu-erh tea(fermented tea) was significantly higher than that of ordinary Pu-erh tea(fermented tea),and the content of EGCG and theabrownins was slightly lower than that of ordinary Pu-erh tea(fermented tea);For the first time,three "Golden Flower" Fungi were isolated in the process of Pu-erh tea storage,identified as Aspergillus pallidofulvus(similarity 99.9%),Aspergillus sesamicola(similarity 99.8%),Penicillium manginii(similarity 99.6%).Among them,Aspergillus sesamicola is the dominant "Golden Flower" strain,accounting for 66% of the total number of "Golden Flower" flora.This paper identified the "Golden Flower" fungi in Pu-erh tea storage,and analyzed the influence of "Golden Flower" fungus on the quality of Pu-erh tea(fermented tea),which provided a theoretical basis and reference value for the application of "Golden Flower" in Pu-erh tea.