Widely targeted metabolomics analysis of the main bioactive compounds of Ganpu tea processing through different drying methods

The flavor and biological components of Ganpu tea are largely affected by the drying process. In this study, Ganpu tea was selected as the research object, and the effects of different drying methods, including drying by sunlight, low temperatures and hot air, on the antioxidant activities, alpha-glucosidase and acetylcholinesterase activities and metabolite profiles of Ganpu tea were investigated. The results suggested that the DPPH free radical scavenging activities of low temperature-dried Ganpu tea (GPTL), sunlight-dried Ganpu tea (GPTS) and hot air-dried Ganpu tea (GPTH) were 46.8%, 56.2% and 47.1%, respectively. The ABTS radical cation scavenging activity of GPTL, GPTS and GPTH were 45.2%, 51.4% and 46.3%, and the T-AOC activities among them were 14.3, 21.4 and 12.5 U/g, respectively. In addition, compared with GPTS and GPTH, GPTL increased alpha-glucosidase inhibition and acetylcholinesterase inhibition activities. The widely targeted metabolomics analysis showed that low-temperature drying significantly increased corilagin and strictinin levels, which played an important role in the antioxidant activities of Ganpu tea. The results provide a novel method for drying Ganpu tea and help promote the quality control of Ganpu tea during processing.