Enhancing the flavor profile of strong-flavored green tea from Sichuan: Evaluation and optimization study

Abstract

This study evaluated seven taste subfactors of 64 green teas from Sichuan province and categorized them into three types: fresh and mellow (FM), strong and thick (ST), and fresh and strong (FS). The FM-type showed excellent freshness and sweetness, while the ST-type exhibited bitterness, astringency, and strength. Component analysis showed higher water extract and tea polyphenols in the ST-type, with the soluble sugar content correlating positively with taste strength but not sweetness, highlighting the complexity of flavor perception. More exhaustively, we used targeted metabolomics to examine the relevant constituent fractions. The levels of epigallocatechin gallate, epicatechin gallate, epigallocatechin, epicatechin, dihydromyricetin and rutin were highest in ST, and positively correlated with bitterness and astringency. Umami amino acids were found mostly in FM, and were positively correlated with freshness. To optimize the taste quality of ST green tea, two methods were investigated: tea bag confinement leaching and aroma enhancement. Both methods effectively reduced bitterness and astringency. Tea bag confinement leaching can be widely applied to enhance the utilization of summer tea raw materials and elevate the sensory quality of middle- and low-grade green teas. While promising for seasoned tea flavor enhancement and bitter suppression, the aroma enhancement technique requires further research.