Study on Aroma Compounds of Different Grades Shuangjing Green Tea Based on HS-SPME-GC-MS

To investigate the composition characteristics of aroma compounds in different grades of Shuangjing green tea, headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) was used to detect and analyze aroma compounds in four different grades of Shuangjing green tea in Xiushui County. These grades included Shuangjing Yinhao, Shuangjing Green Tea Super Grade, Shuangjing Green Tea First Grade, and Shuangjing Green Tea Second Grade. The results showed that a total of 70 aroma compounds were identified from four different grades of Shuangjing Green tea. These compounds mainly included alcohols, olefins, alkanes, esters, and other compounds. The aroma components and relative contents of Shuangjing green tea varied among different grades. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) effectively distinguished between the different grades of Shuangjing green tea. The aroma changes of different grades of Shuangjing green tea were mainly caused by the relative changes in 14 key compounds, such as trans-β-farnesene, geraniol, methyl salicylate, (Z)-jasmone, phenylethyl alcohol, and so on. The key aroma compounds in different grades of Shuangjing green tea exhibited distinct distribution patterns. Accompanied by the development of buds and leaves, the contents of α-copaene, caryophyllene, and hexanoic acid ethyl ester decreased, whereas the contents of cis-3-hexen-1-ol, geraniol, and methyl salicylate showed an increasing trend. The linalool, (Z)-jasmone, and trans-nerolidol contents increased gradually. However, with the full development of the leaves, the contents of linalool, (Z)-jasmone, and trans-nerolidol decreased rapidly. In summary, this study examined the compositional characteristics of aroma compounds and the distribution patterns of key aroma compounds in four grades of Shuangjing green tea. These findings provide a theoretical basis for the future production of Shuangjing Green Tea.