Abstract:
The aroma components and fungal community compositions of Liu-pao tea were detected using gas chromatography-ion mobility spectrometry and high-throughput sequencing, respectively. Thirteen different aldehydes, nine esters, eight alcohols, eight ketones, two hydrocarbons, one acid, and two heterocyclic compounds were identified along with various integrated aroma characteristics, mainly floral, fruity, sweet and herbaceous. Fungi in the different tea samples varied greatly, with Aspergillus, Rhodotorula, Geosmithia, Wallemia, Penicillium, Blastobotrys, and Fusarium accounting for the majority at the genus level and the most abundant fungi, Aspergillus and Rhodotorula, reaching as high as 82.57% to 99.73% of the total. Correlation coefficients obtained between the abundances of Aspergillus and Wallemia and the relative content of the key aged aroma component, nonanal, were -0.89 and 0.83, respectively. Meanwhile, correlation coefficients of -0.84, 0.97, 0.96, 0.83, and 0.84 were obtained between the abundances of Aspergillus, Rhodotorula, Penicillium, Blastobotrys, Fusarium and linalool oxide (characteristic component of the betel nut aroma), respectively. Aspergillus and Wallemia are thus thought to be involved in the characteristic aged aroma of Liu-pao tea, while Aspergillus, Rhodotorula, Penicillium, Blastobotrys, and Fusarium may be involved in the formation of the betel nut aroma. The aroma characteristics of Liu-pao tea are therefore highly correlated with the composition of the fungal community.
