Contribution of addition theanine/sucrose on the formation of chestnut-like aroma of green tea

Abstract

In this study, a combination of quantitative drying and Maillard reaction was investigated by addition of theanine and sucrose during the final firing process to explore the mechanism of chestnut-like aroma formation. The influence of exogenous additives on the formation of chestnut-like flavor of green tea was characterized by infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), physicochemical components as well as sensory evaluation. The addition of theanine or sucrose separately could improve the chestnut-like characteristics flavor, among which the chestnut-like aroma quality and comprehensive quality of green tea was significantly improved by the addition of theanine/dry tea (5‰ w/w). Significant difference (p < 0.05) was observed among different addition treatments on physicochemical components. In addition, the effect of different drying time (15–75 min) was investigated and the chestnuts-like aroma was significantly improved when the drying time reached 45 min. Moreover, the change trends of two key chestnut-like aroma compounds (methyl salicylate and α-ionone) were well consistent with the sensory evaluation and reached the highest at 45 min. The results would further enrich the basic theoretical system of chestnut-like fragrance and also provide a reference for the processing of chestnut-like aroma of green tea.