Improving the performance of dextran–whey protein isolation microcapsules for the encapsulation of selenium-enriched peptide by Maillard reaction

Selenium-enriched peptide (SP) is a new type of selenium supplement with unique bioactivities; however, its instability jeopardizes its industrial applications. Hence, a system stabilizing and delivering SP is a prerequisite to overcome this defect. This study developed a microcapsule, dextran–whey protein isolate–selenium-enriched peptide (DX–WPI–SP), encapsulating SP within the WPI–DX glycation product via electrospraying technology, and its properties were characterized. Results showed that DX–WPI–SP considerably surpassed the physical mixture of WPI, DX, and SP, with respect to antioxidant capacity, thermal stability, and cell cytotoxicity. The in vitro gastrointestinal digestion results showed that over 42% of the SP in DX–WPI–SP survived the gastric fluids and was then released in the intestinal phase. The stability of SP in long-term storage was also observed after its encapsulation in DX–WPI–SP, signifying its stability in this delivery system. This study demonstrated that the DX–WPI–SP microcapsule is a valid strategy to stabilize SP in intestinal delivery.