Identification of key odorants responsible for cooked corn-like aroma of green teas made by tea cultivar 'Zhonghuang 1'

Abstract

Fangping green tea (FPGT) produced by Zhonghuang 1 (C. sinensis var. sinensis cv. Zhonghuang 1), a new tea variety, has a classical cooked corn-like aroma, which is completely different from the green tea aroma. In order to illustrate the aroma characteristics of the green tea, the volatiles of FPGT was analyzed with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). The results showed that odor activity value (OAV) of dimethyl sulfide (DMS) was 1195.21 and the odor intensity about DMS was 6.2 in FPGT. Aroma recombination experiment also confirmed the important contribution of DMS to cooked corn-like aroma. Aroma character impact (ACI) values of DMS in tea processed by Zhonghuang 1 and Fudingdabai were 72.01% and 37.86%, respectively. This indicated that the high proportion of DMS was the dominant character of green tea with cooked corn-like aroma. In addition, the S-methylmethionine (SMM) content in fresh leaves of Zhonghuang 1 (0.21 mg/g) was significantly higher than that of Fudingdabai (0.16 mg/g), which was an important reason for high DMS content.

Keywords: Aroma recombination; Cooked corn-like aroma green tea; Dimethyl sulfide; GC-O; OAV; S-methylmethionine; Zhonghuang 1.