Different grades of green tea 'Duyun Maojian': a comprehensive constituent, bioactivity, and sensory evaluation from...

Duyun Maojian is a geographical-landmark product of Guizhou, with the processing technology included on the list of intangible cultural heritage. There are a few reports on the processing features of this green tea. This study investigated differences among five grades of Duyun Maojian by integrating objective component analysis with subjective aspects, including functional and sensory evaluations. The GC-MS analysis identified 78 key differential aroma components, primarily terpenes, alkanes, and esters, that contributed to the differences. LC-MS/MS data identified 23 key differential metabolites, including flavonoids and amino acids, as the primary differential metabolites for grade discrimination. Antioxidant, anti-inflammatory, and anti-thrombotic assays demonstrated the significant potential of Duyun Maojian for vascular protection. Sensory evaluation revealed grade-dependent variations in bitterness and umami that align with trends in TPC and TFAA. This study indicated that picking timing, picking part, and processing applicability play vital roles in determining tea quality, and smell is an essential basis for grading.