Metabolomic Evidence for Bee-Driven Detoxification, Nutritional Remodeling, and Geographic Homogenization in Rapeseed Floral Products

Background: Rapeseed (Brassica napus L.)-derived pollen, pollen-containing anther, bee pollen, and honey are natural health products with both nutritional and functional value. Bee processing plays a key role in the dynamic transformation process of bee product formation. Existing research has mostly focused on static analyses of single product types and has not systematically elucidated the hierarchical differences in metabolites from plant pollen to bee products, the remodeling mechanism during bee processing, or the impact of geographical origin and agricultural practices on product metabolic profiles. These research gaps limit the precise development and quality control of rapeseed-derived bee products. Methods: This study employed UPLC-MS/MS-based untargeted metabolomics to analyze differential metabolites among rapeseed pollen, pollen-containing anther, bee pollen, and honey and elucidated functional differences via KEGG pathway enrichment analysis. Results: A total of 1308 metabolites were identified, primarily consisting of active components such as flavonoids and terpenoids. Origin-related differences caused by agricultural practices and companion plants were significant in raw pollen but were markedly attenuated by bee processing. Bee pollen showed increased levels of phospholipids and sugars along with reduced toxic substances, forming a safer and more balanced nutritional profile, making it suitable as a nutritional supplement. Honey was highly enriched in monosaccharides and disaccharides, combining flavor with functionality, and is suitable for the development of energy foods. Conclusions: Bee processing actively reshapes the pollen metabolome, attenuates geographical origin differences in raw materials, and enhances the safety and nutritional balance of bee products.