红茶菌发酵普洱茶茶汤过程中主要成分变化

Variations in Major Components of Pu-erh Tea Infusion during Fermentation by Kombucha Culture

以蔗糖(50g/L)、不同贮藏年份的普洱茶(8g/L)为主要原料制成的糖茶水,经微孔滤膜除菌后接种红茶菌母液发酵,于28℃恒温静置培养8d,研究微生物总数、pH值、茶多酚、总酸度、蛋白质含量、成膜生物量及发酵液中高沸点物质的动态变化规律。结果表明:采用普洱茶茶汤培养的红茶菌,发酵过程中各项基本指标(如微生物总数、pH值等)的变化规律与采用绿茶或红茶茶汤发酵没有多大差异,说明普洱茶茶汤是培养红茶菌的较好原料;发酵过程中采用GC-MS从发酵液中共鉴定到了35种非挥发性成分,其中主要是醇类(14种)和酸类(13种),发酵初期(0～4d)以产生醇类物质为主,之后则以酸类物质为主;柠檬酸、nonahexacontanoic acid、2,6-十六烷基-1(+)-抗坏血酸酯等物质出现在菌液成熟期(7d),可能是成熟的红茶菌菌液中起保健作用的关键成分。

Different storage-age Pu-erh tea（1,5,10 years） infusion（8 g/L） sweetened with sucrose 50 g/L was filtrated and inoculated with kombucha culture for 8-day fermentation at 28 ℃.The fermentation broth was dynamically analyzed for microbial population,pH,tea polyphenols,total acidity,protein and biomass as well as high-boiling-point substances.Results showed that there were no obvious differences in microbial population,pH values,etc.between Pu-erh and green or black tea infusion fermented by kombucha culture.Therefore,Pu-erh tea infusion was an excellent matrix for kombucha fermentation.Added together,35 non-volatile components（mainly including 14 alcohols and 13 acids） were identified by GC-MS in different storage-age Pu-erh tea infusion fermented by kombucha for 3,4,6,7 days and 8 days.Alcohols were detected with the most frequencies at the initial fermentation stage（0-4 days）,and acids were dominant later.Citric acid,nonahexacontanoic acid,l-（＋）-ascorbic acid,2,6-dihexadecanoate,etc.were detected in the maturation period（the 7th day）,which may be the crucial constituents in favor of health in fermented Pu-erh tea infusion by kombucha.