BIOTRANSFORMATION OF GREEN TEA (CAMELLIA SINENSIS) WITH YEASTS AND LACTIC ACID BACTERIA

Abstract

Aroma compounds and non-volatile components such as polyphenols and alkaloids are two crucial determining factors of tea quality. These factors can be significantly influenced by microbial fermentation. This research investigated the effects of yeasts and lactic acid bacterial fermentation on aroma compounds and non-volatile components of green tea. Saccharomyces and non-Saccharomyces yeasts showed different characteristic effects on the chemical constituents of green tea. S. cerevisiae generated ethyl esters, whereas non-Saccharomyces (Pichia kluyveri and Cyberlindnera mrakii) elevated acetate esters in fermented tea. In addition, C. mrakii showed β-glucosidase activity that increased some key tea aroma compounds such as methyl salicylate. Torulaspora delbrueckii and P. kluyveri significantly improved the antioxidant capacity of fermented teas, while S. cerevisiae had no such an effect. Two probiotics, Saccharomyces boulardii and Lactobacillus plantarum, presented a synergistic effect on flavor modulation of green tea, while S. boulardii significantly enhanced the survival of Lb. plantarum during storage.