Seasonal Differences on Aromatics in Sichuan Black Teas

The aromatic components of Sichuan black teas produced in spring, summer, and autumn were determined using SPME-GC-MSfor comparison. A total of 107 such compounds were detected in the samples. The spring black tea had 81;the summer tea,46; and, the autumn tea, 79. The 31 of them that were commonly found in all 3 teas were linalool and its oxides, geraniol, methyl salicylate, benzene ethanol, and nerolidol. The major substances contributing to the aroma of these teas included 18 geraniol, linalool, and methyl salicylate in the spring product, 15 benzene ethanol, linalool oxide Ⅱ, linalool oxide Ⅳ, and 3,7-dimethyl-1,5,7-octatrien-3-ol in the summer sample, and 18 geraniol, linalool, benzene ethanol, and 3,7-dimethyl-1,5,7-octatrien-3-ol in the autumn tea. The predominant floral and fruity fragrancein the spring and autumn black teas was attributed to the contents of geraniol, linalool, and methyl salicylate;whilethe orange note in the summer and autumn teas was thoughtto possibly come from 3,7-dimethyl-1,5,7-octatrien-3-ol. The Wickremashinghe-Yamanishi indices of the spring, summer, and autumn teas were 0.26, 0.62, and 0.23, respectively, indicating that the spring and autumn black teaswere more highly aromatic than the summer variety. A same conclusion was also drawn fromthe sensory evaluation.