Analysis of the Bitter and Astringent Taste of Baked Green Tea and Their Chemical Contributors

The paper discussed the quantitative analysis of the bitter and astringent taste of the baked green tea and the main chemical component contributors. Baked green teas made of fresh tea leaves with different tenderness were used as the raw material to analyze the taste attributes(including bitterness, astringency, umami, and mellowness) and contents of quality components by quantitative sensory evaluation and chemical analysis, and synchronously establish the correlation between them. The results showed that, with the decrease of tea leaves tenderness, the bitter, astringent and umami taste of the tea infusions decreased as well as the total taste quality. Through analyzing the quality components and their taste contributions, it was found that the main contributors for the bitterness of the baked green tea were EGCG and caffeine, and for the astringency were catechins and flavonoid glycosides. EGCG was the main catechin component for astringent taste, and EGC and ECG also had significant contribution. Que-rut and Que-gala were the main flavonoid glycosides, other glycosides including Myr-gala, Que-glu, Vit-rha, Kae-gala, Kae-rut, Kae-glu also had significant contribution for astringent taste. The analysis of the Dot values showed that free amino acids had no significant contribution to the umami tatste. This research preliminarily illuminated the main chemical contributors for the bitter and astringent taste of the baked green tea and p rovided theory basis for the tea-quality improvement and taste-chemistry study.