The aroma of an instant white tea (IWT) was extracted through simultaneous distillation–extraction (SDE) and analyzed by sensory evaluation, gas chromatography-mass spectrometry-olfactometry (GC-MS-O), aroma reconstruction, omission test and synergistic interaction analysis. Sensory evaluation showed the IWT was dominated with floral and sweet notes. The SDE extract had the aroma similar to the IWT. The main volatile components in the SDE extract were benzyl alcohol, linalool, hotrienol, geraniol, α-terpineol, coumarin, camphene, benzeneacetaldehyde, 2-hexanone, cis-jasmin lactone and phenylethyl alcohol. GC-MS-O and aroma reconstruction experiments showed 16 aroma-active compounds. Linalool, trans-β-damascenone and camphene were the major contributors to floral, sweet and green notes based on flavor dilution analysis and omission test. Linalool and trans-β-damascenone had synergistic effect to promote floral and sweet notes. Camphene and trans-β-damascenone had synergistic effect to reduce green and sweet notes. The study helps to understand the aroma of IWT and antagonism interactions among aroma-active volatiles.

The regulation investigation of the uptake, distribution, and accumulation of polycyclic aromatic hydrocarbons (PAHs) in the crop growing is essential for human health risk assessments. As an important crop with Chinese medicine homologous food function, Pueraria lobata (P. lobata) was selected as the model crop with rhizome as the products to explore the absorption, and distribution of PAHs under the natural field environment for the first time. After treated with PAHs in soil at different growth stages, the detailed PAHs in soil and tissue were analyzed. The results showed the agronomics traits of P. lobata had no obvious change after treated with PAHs, especially at the maturity stage. The accumulation of Σ₁₆PAHs in the soil had obvious seasonal dependence, and increased by 31 %, 76 % and 90 % treated with low-, medium-, and high-dose treatment at maturity stage, respectively. The tissues absorption of PAHs were selective with the leaves preferring low-rings and roots for high-rings, due to high-rings PAH being difficult to migrate to the above-ground part through transpiration flow. Notably, low-dose PAHs treatment could promote the production of total polysaccharides and main isoflavone, while medium-dose and high-dose PAHs treatment inhibited their production. The above result confirmed that PAHs could be adsorbed by P. lobata with different routes, roots mainly absorbed PAHs by root uptake from soil, leaves mainly accumulated PAHs by the foliar uptake, and the absorbed PAHs could affect the quality of P. lobata. Based on these results, the concentration of PAHs in the field should be strictly monitored.