发酵条件对红茶菌发酵品质及风味的影响

Effects of Fermentation Conditions on Quality and Flavor of Kombucha

探究发酵条件对红茶菌发酵品质及发酵液风味的影响。以发酵产酸率、感官评分为指标,考察红茶品种、茶叶浸提方式、糖添加量、茶叶添加量及红茶菌膜接种量的影响;同时,对发酵过程中风味物质的变化进行分析。结果表明:将水煮沸后,加0.5%醇香红茶浸提15 min,加入7%糖,冷却后加8%红茶菌膜于30℃条件下发酵10 d,得到的产品感官品质好,发酵液呈清澈淡黄色,酸甜适中,微酸,口味纯;茶汤经发酵后风味物质显著改变,共检测到19种风味成分,其中醇类7种、酯类6种、酸类4种、酚类1种、烷烃类1种,即风味物质多为醇类、酯类和酸类。醇类的含量为25.09%,其中乙醇含量为21.51%;酸类的含量为46.40%,其中正辛酸含量为19.41%;酯类的含量为15.91%,其中乙酸乙酯含量为9.47%。

The objective of this study was to analyze how different fermentation methods can affect the fermentation profile of kombucha in terms of its flavor, fermentation yield (total acid/sugar consumption) and sensory evaluation. The variable factors considered included black tea type, tea extraction modes, concentrations of sugar and tea and inoculum size of starter culture. The optimized conditions for the best quality of kombucha were obtained after adding 0.5% mellow black tea toboiling water and keeping it at room temperature for 15 min, followed by the addition of 7% sugar and 8% komucha starterculture. Finally, the fermentation process was carried out at 30 ℃ for 10 days. After fermentation the broth was clear withpale yellow color, and sweet and moderately sour taste. A considerable change in flavor profile was observed before and after the fermentation under the optimized conditions. A total of 19 volatile aroma compounds were identified including 7 alcohols, 6 esters, 4 acids, 1 phenol and 1 hydrocarbon. The contents of alcohols, acids and esters were 25.09%, 46.40% and 15.91%, respectively.