Profiling Real-Time Aroma from Green Tea Infusion during Brewing.

Litao Sun,Yonglin Ren,Xue Dong,Manjree Agarwal,Zhaotang Ding,Alexander Ren

doi:10.3390/foods11050684

Abstract

Aroma substances are the most crucial criteria for the sensory evaluation of tea quality, and also key attractors influencing consumers to make the decision for purchasing tea. Understanding the aromatic properties of tea infusion during different brewing time is crucial to control the tea aromatic quality. Here, headspace and direct immersion solid-phase microextraction (HS-SPME and DI-SPME), coupled with GC-MS, were employed to investigate the impact of brewing time on the changes of the volatile features of green tea infusion. Esters, aldehydes, alcohols, fatty acids, and alkaloids were the predominant volatile groups from tea infusions. Two to three minutes was identified as the best duration for the tea brewing that can maximize the abundance of aromatic chemicals in the headspace emitted from the tea infusions. The variation of the key aromatic contributors between the tea infusion and the headspace over the infusion tended to equilibrate during the tea brewing process. This study provides a theory-based reference method by analyzing the real-time aromatic characteristics in green tea. The optimal time was determined for aromatic quality control, and the complementary relationship between the volatiles in the headspace and its counterpart, tea infusion, was primarily elucidated.

Highlights

Green tea, produced by the tea leaves (Camellia sinensis), is widely appreciated for its cultural connotations, sensory attributes, and health properties, especially in Asian countries [1]
More than 200 Volatile organic compounds (VOCs) have been identified in green tea, including alcohols, aldehydes, acids, ketones, and esters [4]
We systematically explored the changes of VOCs, and the potential regulation that governed their formation or releasing between tea leaves, the tea infusion, and the headspace during tea brewing

Summary

Introduction

Green tea, produced by the tea leaves (Camellia sinensis), is widely appreciated for its cultural connotations, sensory attributes, and health properties, especially in Asian countries [1]. Flavor, color, and appearance are primary aspects for evaluating green tea quality. Aroma is perceived as a leading factor defining tea quality that influences the consumer’s selection, acceptance, and digestion of the tea. Volatile organic compounds (VOCs), as the fundamental metabolites for tea (odor and aroma), occur in tea in small quantities, accounting for 0.01% of dry weight, but are of enormous importance to perceptions of quality [3]. Constant efforts have been devoted to enhancing the aromatic quality of tea, covering various aspects, from the level of tea plant breeding [5], agronomic practices [6,7], and manufacturing processes [8], to exogenous additions [9]

Methods

Results

Conclusion