UPLC-ESI-MS/MS analysis revealed the dynamic changes and conversion mechanism of non-volatile metabolites during green tea fixation

• DOI: 10.1016/j.lwt.2024.116010
• Publication Date: 2024-03-30T04:23:35Z
• Authors: Wen Ouyang; Jingming Ning; Xizhe Zhu; Yongwen Jiang; Jinjin Wang; Haibo Yuan; Jinjie Hua
• Keywords: Phenylpropanoid; KEGG; Metabolic pathway

Fixation is crucial for green tea quality; previous studies were conducted on finished teas and focused the volatile metabolites of tea. However, non-volatile metabolites' (NVMs) evolution formation mechanisms during fixation remain unclear. Here, fixated samples collected at seven different time points stage, dynamic changes NVMs investigated via ultra-performance liquid chromatography-tandem mass spectrometry enzymatic activity analyses. The results showed that contained thermal non-enzymatic stages. Moreover, 1196 (10 classes) detected, significant NVM variations observed "enzymatic thermal" stages, with increasing trends in lipids amino acids, except alkaloids. Furthermore, 160 common differential identified. KEGG analysis revealed unsaturated fatty acid, linoleic acid phenylpropanoid, flavonoid metabolism pathways essential influenced aroma, taste, color formation. These provide a theoretical basis to regulate technology enrich chemical theory processing.