(R)-Linalool is a key indicator of aroma quality levels of a distinctive black tea (Camellia sinensis var. Yinghong No. 9)
Chengshun Liu, Jianlong Li, Miao Wang, Guotai Jian, Chen Zhu, Hanxiang Li, Yongxia Jia, Jinchi Tang, Lanting Zeng
Abstract
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.