Analysis of Aroma Compounds of Yunnan White Tea by Four Drying Methods

To investigate the effects of four drying methods on the aroma quality of Yunnan white tea, headspace solid phase microextraction and gas chromatography mass spectrometry (HS-SPME-GC/MS) combining with relative odor activity value (ROAV) method were used to analyze the volatile components of air drying, air-sun drying, sun drying and bake drying Yunnan white tea. The results showed that 91 effective volatile components were detected, mainly alcohols and olefins volatile component species, with the highest relative contents of linalool, (−)-β-pinene, methyl salicylate, phenylethanol, α-caryophyllene and phenylacetaldehyde. Significant differences in the contents of theaspirane, (E)-3-hexen-1-ol, 1-hexanol, 2,2,3-trimethyl-cyclobutanone, 1-octen-3-ol, 3,5-octadien-2-one, methyl benzoate, (E)-2-octen-1-ol and benzyl alcohol were observed under different drying methods. The results of ROAV method analysis showed that there were six main aroma contributing volatile components of Yunnan white tea, namely 2-heptanol, 1-octen-3-ol, linalool, geraniol, phenylethanol, (−)-β-pinene. The comprehensive evaluation results showed that:

Different drying methods affected the aroma type and quality of Yunnan white tea. Air dried white tea had a faint fragrance and a long processing time. Both the sun drying and the air-sun drying white tea had the flavor of sun exposure. Bake drying white tea had a floral fragrance, short processing cycle and was not easily affected by the environment.