Metabolomics-based discrimination of geographical variability in quality and antioxidant activity of golden mushroom (Floccularia luteovirens) from the Qinghai-Tibet Plateau

The golden mushroom ( Floccularia luteovirens ), a nutritionally valuable edible fungus endemic to the Qinghai-Tibet Plateau, exhibits significant quality heterogeneity across different geographical origins. This study employed ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/ToF-MS)-based metabolomics integrated with multivariate analyses to authenticate specimens from Ganzi (Sichuan, SC), Haibei (Qinghai, QH), and Naqu (Xizang, XZ). Principal component analysis (PCA; Q 2  > 0.98, R 2 Y > 0.99) and partial least squares discriminant analysis (PLS-DA; Q 2  > 0.98, R 2 Y > 0.98) confirmed robust geographical discrimination, identifying 52 lipid-dominated markers as critical discriminators. Region-specific markers included triacylglycerols (TG)(54:6), phosphatidylinositols (PI)(18:2/18:2), phosphatidic acids (PA)(18:2/18:2), diacylglycerols (DG)(33:3), and bioactive compounds (e.g., N -linoleoyl-γ-aminobutyric acid, epoxymurin A) in XZ; phosphatidylcholines (PC)(16:0/18:2), lysophosphatidylserines (LysoPS)(16:0), ergocalciferol, and hydroxylated fatty acids ((9Z,12Z)-15,16-dihydroxyoctadeca-9,12-dienoic acid (dihydroxyoctadecadienoic acid, DiHODE), 2-β-methoxy-1-α,25-dihydroxyvitamin D 3 ) in QH; and cerebrosides, ceramides (Cer)(t20:0/22:0(2OH)), and saturated lipid derivatives (PA)(24:0/24:0) in SC. Nutritional profiling revealed that XZ had the highest unsaturated fatty acid content (49.94 %) and hydroxyl radical scavenging capacity (18.34 %/mg), whereas QH exhibited superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition (87.62 %/mg). Lipidomics analysis indicated that XZ's lipid profile was enriched in polyunsaturated species (e.g., 9-hexadecenoic acid, tricosanoic acid), while QH was characterized by omega-3 fatty acids (9,12,15-octadecatrienoic acid) and SC by medium-chain fatty acids (decanoic acid). Key biochemical differences included peak crude and soluble protein levels in XZ (433.5 mg/g and 83.96 mg/g, respectively), whereas QH exhibited the highest free amino acid content (37.58 mg/g). Hydrolyzed amino acid composition varied by region, with SC displaying the lowest leucine (Leu) and alanine (Ala) concentrations. In terms of polysaccharide and polyphenol contents, SC contained the highest polysaccharide levels (116.72 mg/g), whereas QH had the highest polyphenol content (3.64 mg/g). Antioxidant assays further validated origin-dependent bioactivity, with XZ exhibiting the strongest hydroxyl radical scavenging activity, while SC displayed the lowest DPPH/ABTS activities (73.91 %/mg; 0.2 nM trolox/mg) and FRAP values (0.31 mM FeSO 4 /mg). This metabolomics-driven framework establishes a reliable tool for geographical authentication, supporting quality control and the sustainable utilization of golden mushroom resources in functional food industries.