Sun Litao, Dong Xue, Ren Yonglin, Agarwal Manjree, Ren Alexander, Ding Zhaotang
Tea Research Institute, Qingdao Agricultural University, Qingdao 266109, China.
College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Perth, WA 6150, Australia.
Foods. 2022 Feb 25;11(5):684. doi: 10.3390/foods11050684.
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.
香气物质是茶叶品质感官评价的最关键指标，也是影响消费者做出购买茶叶决策的关键吸引因素。了解不同冲泡时间下茶汤的香气特性对于控制茶叶香气品质至关重要。在此，采用顶空和直接浸入固相微萃取（HS-SPME和DI-SPME）结合气相色谱-质谱联用（GC-MS）来研究冲泡时间对绿茶茶汤挥发性特征变化的影响。酯类、醛类、醇类、脂肪酸和生物碱是茶汤中主要的挥发性成分组。确定两到三分钟为最佳泡茶时长，此时可使茶汤顶空释放的芳香化学物质丰度最大化。在泡茶过程中，茶汤与顶空之间关键香气成分的变化趋势趋于平衡。本研究通过分析绿茶的实时香气特征提供了一种基于理论的参考方法。确定了香气品质控制的最佳时间，并初步阐明了顶空挥发性成分与其对应物茶汤之间的互补关系。
