생엽과 덖음녹차의 휘발성 향기성분 분석

Abstract

Volatile flavor components from fresh and roasted leaves of Thea sinensis L. were extracted by SDE (simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethyl ether (1:1, v/v) as an extract solvent. The volatile extracts were analyzed by GC-FID and GC/MS. Identification of the volatile flavor components was mostly based on the RI of GC and mass spectrum of GC/MS. The total number of 83 volatile flavor components were identified in fresh leaves, and (E)-2-hexenal characterized as green note was the predominantly abundant component. Also, monoterpene alcohols such as linalool and geraniol etc. were identified as major compounds. Major functional group was alcohols including C6-alcohols and monoterpene alcohols accounting for 63%, and aldehydes followed by second functional groups. They were considered as important compounds contributing fresh leaves like flavor. But unlike roasted leaves, theaspirans which is identified in Osmanthus fragrance were detected in fresh leaves. They are used in cosmetics and foods. Volatile flavor components of 73 were identified in roasted leaves of T. sinensis L., and the contents was 87.40 mg/kg. 4-Vinyl phenol and 1-ethyl- 1H-pyrrole-2-carbaldehyde were detected as the major volatile compounds accounting for 6.8 and 6.5%, respectively. Appreciable amounts of benzyl alcohol, (E)-nerolidol, indole, ethyl acetate were detected in roasted leaves. The major functional group was alcohols almost consisting of terpene alcohols. Leaf aldehyde such as (E)-2-hexenal and leaf alcohol such as hexanol detected in fresh leaves were significantly decreased in roasted leaves. Esters, ketones, and N-containing compounds produced during heating in roasting process were detected higher than in fresh leaves. As a result, these compounds such as caramel and Maillard reaction products produced by heat could be used for establishment of roasting process to make a green tea having high quality. Also, the results of this study would contribute to the presentation of scientific data about special quality of various tea products for accurate food choice of customers.