The effect of leafhopper saliva on volatiles in the processing of beauty tea

The tea green leafhopper (Empoasca onukii Matsuda) damages tea plants by piercing the leaves with its needle-like mouthparts to suck sap and secrete saliva, with the affected fresh leaves considered the best raw material for producing beauty tea. To investigate the role of leafhopper saliva in the formation of aroma quality in beauty tea, this study extracted leafhopper saliva and applied them to field-grown tea plants. The treated leaves were compared with fresh leaves from unaffected plants, as well as those with low and high leafhopper damage. The study analyzed the dynamic changes in aroma compounds during processing, as along with the major non-volatile quality components, aroma compounds, and sensory qualities of the resulting beauty tea. The results showed that alcohols, esters, and alkenes accounted for over 90 % of the compounds during the processing of beauty tea, with the proportion of alcohols such as (Z)-3-hexenol, benzyl alcohol, and linalool and its oxides increasing sharply after withering and remaining unchanged after panning. Beauty tea made from leaves treated with leafhopper saliva exhibited high levels of methyl salicylate, linalool, and dehydrolinalool, along with high free amino acid content and low tea polyphenol content, resulting in a tea infusion with floral, fruity, fresh, and sweet notes. The study found that applying aqueous leafhopper saliva to mechanically damaged leaves effectively simulates natural leafhopper feeding and produces high-quality beauty tea. These findings provide a theoretical basis for understanding tea plant-leafhopper interactions and producing high quality beauty tea.