Unraveling the chemosensory attributes of Chinese black teas from different regions using GC-IMS combined with sensory analysis

Abstract

This study aimed to investigate the effect of planting regions on the aroma quality of Chinese black tea by chemical and sensory profiles. Thus, a total of 99 volatile compounds in black tea samples made from four provinces of China were identified by gas chromatography-ion-mobility spectrometry, among which the amounts of 55 compounds were significantly different. The sensory analysis showed all black tea samples had the sweet note. Additionally, the characteristic aroma attribute of Keemun black tea was floral odor, Yichang black tea evoked herbal/minty note, while Dian black tea and Yingde black tea evoked sweet potato-like/plum-like note. The results of partial least squares regression and network analysis showed significant amounts differences of 25 volatiles such as benzeneacetaldehyde, (Z)-3-hexenol, γ-nonalactone, and linalool were responsible for the region related-aroma characteristics of four black teas. Aldehydes, ketones and alcohols mainly contributed to the green, floral, sweet potato-like, and malty attributes, and esters had great contribution to the sweet note. The objectives were providing certain theoretical support for the scientific description of the difference of sensory and chemical basis of black teas in different regions.