泾渭茯砖茶发酵过程中霉菌的变化

茯砖茶发源于陕西泾阳,属于后发酵茶,霉菌是其发酵过程中起重要作用的菌,泾渭茯砖茶是茯砖茶的代表。本研究分析了泾渭茯砖茶发酵过程中的12个不同阶段(0、2、4、6、8、10、12、14、16、18、23、28 d)可培养霉菌的变化,结果表明,发酵过程中参与的霉菌有8种,分别为冠突曲霉(Aspergillus cristatus)、肋状曲霉(Aspergillus costiformis)、橘青霉(Penicillium citrinum)、木贼镰刀菌(Fusarium equiseti)、黑曲霉(Aspergillus niger)、米曲霉(Aspergillus oryzae)、互隔铰链孢霉(Alternaria alternate)和芽枝状枝孢霉(Cladosporium cladosporioides)。其中,发酵前期橘青霉为优势菌群,另外还有少量冠突曲霉、黑曲霉、互隔铰链孢霉和芽枝状枝孢霉;发酵第8 d橘青霉数量仍较多,检出了少量肋状曲霉和黑曲霉,这之后冠突曲霉开始大量生长,在发酵中后期占据主导地位,发酵终点时菌落数量达到134000 CFU/g,占霉菌总数的99.99%。泾渭茯砖茶发酵前期霉菌菌群丰富,随着发酵的进行,其中的冠突曲霉逐渐成为优势菌群。

Changes of Molds in Jingwei Fuzhuan Brick Tea during Fermentation

Fuzhuan brick tea originated in Jingyang, Shaanxi province and belongs to post-fermented tea. Molds play important roles in the fermentation of Fuzhuan brick tea. Jingwei Fuzhuan brick tea is a typical representative of Fuzhuan brick tea. In this work, the changes of culturable molds in 12 different stages (0th d, 2nd d, 4th d, 6th d, 8th d, 10th d, 12th d, 14th d, 16th d, 18th d, 23th d, 28th d) during the fermentation of Jingwei Fuzhuan brick tea were analyzed. The results showed that there were eight kinds of molds involved in the fermentation process, which were Aspergillus cristatus, Aspergillus costiformis, Penicillium citrinum, Fusarium equiseti, Aspergillus niger, Aspergillus oryzae, Alternaria alternate and Cladosporium cladosporioides. In the early stage of fermentation, Penicillium citrinum was the dominant mould group, and there were a small amount of Aspergillus cristatus, Aspergillus niger, Alternaria alternate and Cladosporium cladosporioides. On the 8th day of the middle fermentation period, there was still a large amount of Penicillium citrinum, and a small amount of Aspergillus costiformis and Aspergillus niger were also detected. After that, Aspergillus cristatus began to grow in large quantities and occupied a dominant position in the middle and late fermentation period. At the end of fermentation, Aspergillus cristatus were to be 134000 CFU/g and accounted for 99.99% of all molds. Fungal flora is rich in the early stage of Jingwei Fuzhuan brick tea fermentation. With the fermentation progress, Aspergillus cristatus gradually become the dominant flora.