Metabolomics analysis reveals dynamic changes in the quality components and antioxidant activity capacity during...

This study analyzed the dynamic changes in the quality components of Jinsihuangju (Chrysanthemum morifolium) tea using metabolomics during variable temperature drying (VTD). VTD significantly increases the content of phenolic compounds and total flavonoids, while the total amino acid content decreases but not significantly. Using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), a total of 68 volatile components (VOCs) were identified, with 20 distinct aroma components selected, eight key aroma components including α-pinene，α-farnesene, β-myrcene, and caryophyllene were identified as significantly contributing to the fruit, woody, and spice characteristics of finished tea. Ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-orbitrap-MS) screening identified 409 non-volatile components (NVOCs), with 126 showing differential expression. Among these, significant variations in flavonoids, glycosides, and lipids not only influence the taste of chrysanthemum tea but also play crucial roles in functional properties. Furthermore, VTD enhances the antioxidant capacity of JSHJ tea, likely due to the significant increase in functional components such as luteoloside, isovitexin, luteolin, apigenin 7-O-glucoside. This study provides a reference for better understanding the formation mechanism of JSHJ tea quality.