The influence of Lactobacillus plantarum fermentation in selenium-enriched Brassica napus L.: changes in the nutritional constituents, bioactivities and bioaccessibility

Selenium (Se)-enriched Brassica napus L. is a valuable organic Se supplement. In this study, the fermentation broth enriched with organic Se (FFS) was prepared using Lactobacillus plantarum to ferment the substrate of Se-enriched Brassica napus L. Significant increases were observed after fermentation in total sugars, reducing sugars, soluble proteins, total phenolic content (TPC), and total flavonoid content (TFC). The organic Se was retained at a concentration of 54.75 ​mg/g in the freeze-dried sample. Principal component analysis and cluster analysis showed good separation between the FFS and unfermented (FS) groups. Fragrant 2-ethyloxetane had the highest content among all volatiles, while sinapine had the highest content among all phenolic compounds. The fermentation process showed remarkable improvement in the abundance and concentration of volatile compounds and phenolic contents, making FFS exhibit strong antioxidant activity and inhibitory capacity against α-glucosidase activity. The bioaccessibility of phenolic compounds was significantly greater in FFS compared to FS. ADMET analysis revealed that the majority of phenolic compounds contained in FFS did not exhibit mutagenicity toxicity, hepatotoxicity, skin sensitization, or blood-brain barrier penetration, indicating a favorable level of biosafety. Overall, our study provides a new insight into the further utilization of Se-enriched Brassica napus L. in foods.