Dynamic changes in flavor characteristics of black tea during solid-state fermentation with Eurotium cristatum

Abstract

This study employed GC-MS, GC-IMS, and sensory evaluation to investigate dynamic changes in flavor during the solid-state fermentation of black tea by Eurotium cristatum. The results revealed a notable decrease in the bitter and astringent tastes of the black tea infusion following fermentation, while the mellow taste increased significantly. A total of 152 and 129 VOCs were detected by GC-MS and GC-IMS, respectively. And 4 key aroma-active compounds were identified by ROAV. These specific VOCs contributed floral, honey, and sweet scents, which were responsible for the fungal floral aroma in the processed black tea. Furthermore, OPLS-DA identified 31 key VOCs that played a crucial role in differentiating various fermentation stages, with day 4 recognized as a pivotal point for aroma development. The solid-state fermentation with Eurotium cristatum resulted in fermented black tea characterized by a mellow taste and a rich fungal floral aroma, enhancing the flavor quality of the tea.

Keywords: Black tea; E-nose; Eurotium cristatum; GC-IMS; GC–MS; Sensory evaluation.