Abstract:
To investigate the flavor quality characteristics of broken black tea from different regions, representative samples from four regions, namely, Yunnan, Guangxi, Guizhou, and Hubei, were selected to analyze the quality differences of broken black tea from different origins employing sensory evaluation, chemical composition and aroma compound detection, combined with chemometric methodologies, taste activity value (TAV), and odor activity value (OAV). Results showed that significant disparities existed in the taste and flavor quality components of broken black tea across different regions. For instance, the Yunnan sample had the highest sensory evaluation scores, while the Hubei sample had the highest contents of caffeine (1.47%) and water extract levels (51.01%). The Guangxi sample exhibited elevated concentrations of tea polyphenols (17.28%), total catechins (10,594.58 μg/g) and free amino acids (17913.09 μg/g) relative to other regions. Moreover, 13 substances-caffeine, epigallocatechin (EGC), epigallocatechin gallate (EGCG), epicatechin (EC), epigallocatechin gallate (ECG), catechin gallate (CG), catechin (C), isoleucine, lysine, aspartic acid, glutamic acid, alanine, theanine (TAV>1) -were identified as the main contributors to the taste substances. A total of 76 aroma components were identified across the samples, with alcohols and aldehydes emerging as the primary aroma constituents, while the Guizhou sample had the highest content of aroma components (4898.50 μg/kg). Notable contributors to the sweet and floral aroma of broken black tea included linalool, hexanal, trans-nerolidol, myrcene, 3,5-octadien-2-one,
β-ionone, benzaldehyde, benzyl alcohol, and
β-cyclocitral, 10 components (OAV>10). The Guangxi and Yunnan samples derived their rich floral and sweet aroma from methyl linalool and 3,5-octadien-2-one (OAV>100), respectively. Characteristic aroma substances were also observed, with cis-4-heptenal distinguishing the Guizhou sample. Additionally, the combined aroma compositions of the two groups of broken black tea samples from Hubei and Yunnan were relatively similar. Overall, this study provides a comprehensive analysis of flavor and quality in broken black tea across different regions, which enhancing the understanding of its quality components.