Jasmine tea is produced by repeatedly blending processed tea leaves with fresh flowers of Jasminum sambac, allowing the tea to absorb their characteristic aroma. Because jasmine plants are vulnerable to diseases and insect pests, pesticides may be required to protect yields and flower quality. However, no pesticides are currently registered specifically for jasmine flowers in China, and limited guidance can contribute to inappropriate or excessive application. Previous studies have also reached conflicting conclusions about whether pesticide residues on flowers transfer to tea during scenting. A systematic investigation covering cultivation, scenting, commercial products and brewing was therefore needed to clarify how residues behave and whether they pose risks to consumers.
A study (DOI:10.48130/bpr-0026-0011) published in Beverage Plant Research on 26 August 2026 by Li Zhou's team, Chinese Academy of Agricultural Sciences, shows that the compounds dissipated rapidly in jasmine buds but transferred progressively into tea during scenting, while estimated dietary risks from drinking the resulting infusion remained acceptable.
The researchers conducted field trials in a jasmine-growing area of Hengzhou, Guangxi, China, applying chlorfenapyr, cypermethrin, fenpropathrin, hexaconazole and λ-cyhalothrin at doses recommended for tea plants. Jasmine buds were sampled from two hours to 14 days after application, and residue changes were fitted to first-order kinetic models. The five pesticides had half-lives of 1.7–4.0 days, confirming relatively rapid dissipation. Hexaconazole dissipated fastest, whereas λ-cyhalothrin persisted longest. Correlation analysis indicated that water solubility was an important determinant of persistence: among these water-insoluble compounds, greater solubility was associated with faster dissipation and a shorter half-life. To examine processing-related transfer, treated jasmine flowers were blended with uncontaminated green tea through three controlled scenting rounds. Residues in the tea increased after each round. After the third scenting, chlorfenapyr, cypermethrin, fenpropathrin, hexaconazole and λ-cyhalothrin reached 0.17, 0.062, 0.20, 0.11 and 0.025 mg/kg, respectively. Their overall transfer rates ranged from 4.2% to 10%. Unlike field dissipation, transfer during scenting showed no clear relationship with the pesticides' physicochemical properties, suggesting that processing conditions—such as flower-to-tea ratio and tea moisture—may exert greater influence. The researchers also analyzed 24 commercial jasmine teas purchased online. Chlorfenapyr, cypermethrin, fenpropathrin and λ-cyhalothrin were detected in 88%, 63%, 67% and 96% of samples, respectively, while hexaconazole was not detected. Most results complied with relevant limits, but 96% of samples exceeded the particularly low EU or US limit used for λ-cyhalothrin. For brewing tests, 3 grams of tea were infused in 150 milliliters of boiling water for five minutes. Calculated chronic and acute risk quotients across different populations and geographic dietary groups were all far below one, indicating acceptable exposure through tea consumption.
Overall, the findings show that rapid pesticide loss in jasmine fields does not prevent residues from entering tea during scenting. Repeated processing can progressively increase residue concentrations, making pesticide choice and pre-harvest timing important even when drinking-related exposure is low. The researchers recommend minimizing pesticides with especially restrictive residue limits, including λ-cyhalothrin and hexaconazole, particularly for export-oriented jasmine tea. By connecting field behavior, processing transfer, market surveillance and consumer exposure, the study offers a practical scientific basis for safer pesticide management throughout jasmine tea production.
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References
DOI
10.48130/bpr-0026-0011
Original Source URL
https://doi.org/10.48130/bpr-0026-0011
Funding information
This research was supported by the National Key Research and Development Program of PR China (Grant Nos 2021YFD1601101, 2022YFD1600803), Innovative Program of the Chinese Academy of Agricultural Science (Grant No. CAAS ASTIP-TRICAAS), and Key Research Project of Tea Research Institute, Chinese Academy of Agricultural Sciences (Grant No. TRI-ZDRW-01-08).
About Beverage Plant Research
Beverage Plant Research (e-ISSN 2769-2108) is the official journal of Tea Research Institute, Chinese Academy of Agricultural Sciences and China Tea Science Society. Beverage Plant Research is an open-access, online-only journal published by Maximum Academic Press. Beverage Plant Research publishes original research, methods, reviews, editorials, and perspectives that advance the biology, chemistry, processing, and health functions of tea and other important beverage plants.