Aroma Analysis of a New Oolong Tea of Golden Guanyin by Gas Chromatography/Mass Spectrometry

Abstract

Golden Guanyin tea from Lishui city, Zhejiang province, is a new variety of Oolong tea with special aromas. To analysis the aroma compounds, two sample preparation methods of tea grinding and water distillation were carried out, then the tea aromas and amino acids were detected. The main aroma compounds were of dimethyl sulfide, butanal, ethyl acetate, butanedial and cyclobutene by the grinding method, as for the distillation method, the aroma compounds detected were of benzeneacetaldehyde, phenylethyl alcohol, benzyl nitrile, Geraniol, indole, cyclopentene, phenylethyl butyrate, nerolidol, methyl jasmonate, 2,2'-dipyridylamine, benzenedicarboxylic acid, cyclopentaneacetic acid, methyl jasmonate ester, dibutyl phthalate and phytol. Golden Guanyin tea samples had 16 kind amino acids, in which glutamic acid and leucine were of 0.047 and 0.041 mg/mL, respectively, and the minimum ones were of cysteine and methionine in concentration of 0.004 mg/mL. The results will be helpful in the quality improvement and production of the new Golden Guanyin tea.