Effects of different drying methods on the structure, bioaccessibility, and bioavailability of selenium-enriched peptides from soybean sprouts

Selenium-enriched peptides (SePPs) were isolated from Se-enriched soybean sprouts as the selenium (Se) supplement. The preparation of SePPs was optimised, and their Se content, stability during drying, and absorption properties, were examined. The maximum in vitro antioxidant activity of SePPs was achieved after 5 h of alcalase, at 50 °C, pH 9, 3 % substrate concentration, and 5 % enzyme concentration. 58 peptides containing SeMet or SeCsy were found. Following different drying methods, the Se content dropped, and the cross-linked SePPs produced by freeze-drying had higher hydrophobicity, reduced free sulfhydryl concentration, and more potent in vitro antioxidant activity. In the Caco-2 monolayer cellular transport model, the transport efficiency of SePPs were significantly higher than those of selenite, and the binding of peptides enhanced the bioaccessibility and bioavailability of Se. The study elucidated the structure, composition, morphology bioaccessibility and bioavailabilityand of SePPs, providing support for SePPs functional food development. [Display omitted] •The optimal selenium-enriched peptides preparation method was achieved with alcalase under specificity condition.•58 peptides containing SeMet or SeCsy were identified.•Selenium-enriched peptides have higher bioaccessibility and bioavailability than both selenium-enriched proteins and inorganic selenium.•Drying affects the structure of selenium-enriched peptides, and further affect its antioxidant activity and digestion characteristics.