Drying-Induced Changes in Metabolite Profiles and Antioxidant Activity of Cordyceps militaris: Insights from Integrated Metabolomics and Network Pharmacology.

Cordyceps militaris, a medicinal and edible mushroom, is renowned for its bioactive constituents and health-promoting effects. This study investigated the effects of vacuum freeze drying (VF), vacuum drying (VD), oven drying (OV), and sun drying (SU) on the metabolite profiles and antioxidant activities of C. militaris. VF showed the highest levels of total phenolics, total carotenoids, cordycepin, and N6-(2-hydroxyethyl)-adenosine, whereas VD better preserved total flavonoids. VF- and VD-treated samples also exhibited stronger antioxidant capacities than those processed by OV and SU in 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS•+), hydroxyl radical (•OH), and ferric reducing antioxidant power (FRAP) assays. Metabolomics analysis identified 193 significantly altered metabolites after drying treatments. VF, VD, and SU increased carbohydrates, vitamins, and phenolic acids, while leading to reductions in amino acids, nucleotides, and fatty acids. KEGG analysis revealed that drying significantly affected pathways related to purine and pyrimidine metabolism, amino acid biosynthesis, and phenylpropanoid biosynthesis. Network pharmacology further identified 8 key compounds potentially associated with antioxidant effects through interactions with 37 core targets. These findings highlight the importance of selecting appropriate drying methods to preserve the bioactive compounds and functional quality of C. militaris.