Innovative Tangyang Congou black tea, also known as Minkehong black tea (MKH), is of high quality and hence has gained a reputation on the market. In this study, standard samples of MKH were used as the research material, and the results of sensory evaluation showed that the overall quality of MKH decreased along with the downgrading. The radar chart showed a strong association between higher grades and specific aroma and taste character. Based on the detection of ultra-performance liquid chromatography–mass spectrometry (UPLC–MS) and related analysis, the content of both the ester-type catechins and non-ester catechins decreased along with the downgrading, and the details of their change trends were revealed. The content and dynamic changes in caffeine were also investigated. A total of 19 kinds of amino acids (AAs) were clustered; among them, 4 kinds of AAs, namely, Thr, Leu, Asp, and Ile, significantly contributed to the taste of the tea. Notably, the content of Thr had the highest correlation with the grade of MKH, and the correlation coefficient was 0.991 (p< 0.01). According to gas chromatography–mass spectrometry (GC–MS) detection and analysis, a total of 861 kinds of volatile compounds were detected, the aroma-active compounds in different grades were selected, and an aroma wheel of MKH was constructed. Our results found that non-volatile and volatile compounds not only contribute to defining the level of MKH standard samples but also provide a chemical basis for the measurement of flavour and quality of MKH.
Jianghua Kucha (JHKC) is an ancient tea germplasm, which presents a high value for resource utilization but was less developed in aroma research. In this study, volatile metabolites in fresh leaves and corresponding black teas of JHKC, along with odorants of JHKC black teas were systematically investigated using stir-bar sorptive extraction in combination with gas chromatography–mass spectrometry (GC–MS) and GC–olfactometry/MS (GC–O/MS) technologies. A total of 128 and 135 volatile compounds were identified in fresh leaves and black teas, respectively, along with 13 key differential volatile components derived from fatty acids, pigments, glycoside precursors, and the terpene pathway. An odorant wheel for JHKC black teas was developed based on 29 important odorants determined through a combination of GC–O/MS perception, aroma extract dilution analysis, odor activity value measurement. Trans - β -Damascenone, cis -jasmone, and cis -jasmin lactone have been identified as significant contributors to the “sweet” flavor of JHKC black teas.
危险品化学品经营许可证（带存储）