Effects of storage environments on flavor formation in Ancha tea

Ancha tea (ACT) is a distinctive type of dark tea that primarily undergoes flavor transformation through natural storage processes. Consequently, different storage environments lead to variations in its flavor profile. This study investigated the flavor differences of ACT stored for three years under three distinct natural environments: Beijing (11–13 °C, 50–60% RH), Shanghai (15–19 °C, 69–74% RH), and Foshan (22–24 °C, 73–78% RH). Combined molecular sensory omics and metabolomics analyses revealed that with increasing storage temperature and humidity, the aroma of ACT shifted from sweet and roasted notes to stale and woody notes, and the differential compositional proportions of 13 key aroma compounds were responsible for the observed aroma variations. Regarding taste, elevated storage temperature and humidity facilitated the attenuation of bitterness and astringency in the tea infusion, and this effect was largely ascribed to the decline in key non-volatile compounds, such as catechin-3-O-gallate, epigallocatechin gallate, dihydroquercetin, epicatechin, and epigallocatechin. This study elucidates the flavor characteristics of ACT formed under different storage environments, providing a scientific basis for the targeted regulation of storage conditions and offering consumers a reference for selecting ACT according to their preferences.