Enhancing tea aroma and quality through Kluyveromyces marxianus YE27 fermentation: A novel approach for microbial-fermented tea production

Novel types of microbial-fermented tea should be developed more stably and safely. In this study, Kluyveromyces marxianus YE27 was used to ferment black tea. Results indicated that the grassy aroma in the tea considerably decreased and transformed into a tropical floral and fruity aroma after 48 hours of fermentation. The percentages of aldehydes and ketones decreased from 18.15% to 1.01% and 11.93% to 4.51%, respectively, after 48 h fermentation, whereas the percentage of esters with a fruity aroma increased from 0.68% to 32.72%. The concentrations of trans -linalool oxide and phenylethyl alcohol, which have a floral aroma, also increased from 3.67 to 6.96 μg/g and 0.84 and 2.28 μg/g, respectively. The tea quality considerably improved after K. marxianus YE27 fermentation for 48 h. The results indicated that the fermentation process of tea leaves can be achieved by pure culture inoculation. These findings demonstrate the potential of using pure microbial cultures in fermentation, providing a novel and safe method for producing microbially fermented tea. • Emphasis on developing stable and safe microbial-fermented tea. • Kluyveromyces marxianus YE27 used to ferment black tea. • Significant improvement in tea quality after 48 hours of fermentation. • Easier control and shorter fermentation time suitable for industrial production.