Widely targeted metabolomics analysis and antioxidant properties of Camellia oleifera seeds of different cultivars

• 1339 metabolites were identified in the Camellia oleifera seeds of four cultivars. • Flavonoids and phenolic acids were main specialized metabolites in C. oleifera seeds. • 330 metabolites showed significant differential accumulation among four cultivars. • Flavonoids biosynthesis pathway was significant in four C. oleifera cultivars. • Foundation laid for breeding cultivars with high phenolics and antioxidant activity. Camellia oleifera has attracted significant attention due to its seed oil. However, there is limited information available on the metabolites of Camellia oleifera seeds. In this study, we compared the seed metabolites of four Camellia oleifera cultivars (CL4, CL18, CL40, and CL53) using a UPLC-MS/MS-based widely targeted metabolomics approach. A total of 1339 metabolites, categorized into 13 distinct classes, were identified. Comparative analysis revealed that there were obvious differences in the metabolic profiles of Camellia oleifera seeds, with 330 metabolites showing significantly differential accumulation among four cultivars. Notably, substantial variations were observed in the accumulation of flavonoids and phenolic acids. Metabolic pathway analysis of differential metabolites highlighted significant enrichment in the "biosynthesis of quercetin aglycones II" and "flavonoid biosynthesis" pathways. Antioxidant assays demonstrated that CL53 seed samples exhibited the highest antioxidant capacity. Overall, this study provided scientific support for Camellia oleifera cultivar selection and high-value utilization of Camellia oleifera seeds.