Camellia sinensis var. assamica is a major variety used to produce black tea. However, the core compounds influencing its aroma quality are unknown. In this study, Yinghong No. 9 black tea (YJBT), a distinctive black tea in South China, was analyzed. We detected 44 aroma compounds and identified seven key contributors, namely linalool, geraniol, trans -linalool oxide (furanoid), hexanal, methyl jasmonate, phenylacetaldehyde, and β-ionone. Linalool, which was generally more abundant in spring tea than in summer tea, contributed significantly to sweet and floral aromas. ( R )-Linalool was the primary linalool form in Yinghong No. 9, wherein it was highly abundant in high-quality tea leaves. The substantial expression of a linalool synthase gene and the relatively high catalytic efficiency of the encoded enzyme likely contributed to the accumulation of ( R )-linalool. This study identified the primary aroma compounds in YJBT, providing a foundation for advancing our knowledge of the aromatic quality of black tea.
Each type of tea has a unique volatile profile due to its variety, processing technologies and origin. Using HS-SPME and GC/MS, we analyzed the changes of volatile components in cultivar Yinghong No. 9 during pile-fermentation every 10 days. A total of 94 compounds showed significant differences during a total of 60 days mainly including alkanes, ketones, esters, terpenes, aromatics and heterocyclic compounds. Interestingly, 13 metabolites were progressively reduced during the first 20 days and remained unchanged in subsequent procedures, while 17 metabolites remained unchanged in the early stage and progressively increased during the last 20 days of pile fermentation, indicating that they are characteristic volatile compounds of raw material sun-dried green tea and dark tea, respectively. β-ionone, phenylethyl alcohol, and a-ionone could be the top three contributed aroma compounds in the final dark tea. Our study provides a theoretical basis for process and quality improvement of Yinghong No. 9.
危险品化学品经营许可证（带存储）