Effect of storage time on the metabolites and quality of Meixian green tea

The taste and flavor characteristics of tea are clearly affected by the storage time; however, little is known about the quality and chemical characteristics of aged green tea. In this study, changes in the taste, color, volatile compounds, and bacterial composition of Meixian green tea (MXGT) over different storage periods were investigated. Based on a random forest model, three volatile compounds (dihydroactinidiolide, methyl salicylate, and jasmon) were significantly related to the storage time and classification of MXGT. At representative time points (1, 10, and 20 years), the bacterial compositions were similar to those of fermented tea, and fermented bacteria were found in MXGT after a storage period of 10 years. In general, MXGT clearly changed during storage for different durations, with a relatively stable nutrient composition but substantial changes in aroma compounds. These findings improve our understanding of the properties of aged green tea may guide future production.