Quality Changes of Jinggu Big White Tea during Different Aging Years

To study the quality changes of Jinggu Big White Tea during storage over different years,samples aged from 1 to 7 years were collected. Sensory evaluation, biochemical component analysis, and taste activity value (TAV) calculation were conducted to assess quality variations. The sensory evaluation revealed that with prolonged storage, the aroma of the tea shifted from floral and sweet to a stale aroma, with samples aged over five year being dominated by stale aromas. The taste also transformed from fresh and sweet to mellow. With increasing aging years, the content of certain compounds such as gallic acid, ellagic acid, rutin, myricetin, quercetin, and luteolin increased significantly; while most amino acids and catechin decreased, and the level of caffeine and certain amino acids such as phenylalanine fluctuated. Additionally, seven characteristic components with TAV＞1 were identified, including caffeine, epicatechin gallate, and epigallocatechin gallate responsible for bitterness, and epigallocatechin, epigallocatechin gallate, epicatechin gallate, and gallic acid responsbile for astringency. This study clarified the variations in sensory quality and characteristic taste compounds of Jinggu Big White Tea at different storage years, providing a foundation for systematic analysis of its aging mechanism.