Selenium Speciation and Stability in Selenium-Enriched Bean Sprouts During Cultivation and Processing

In selenium-rich foods, selenium speciation significantly impacts food quality. This study cultivated selenium-enriched bean sprouts using various selenium sources and systematically examined the dynamic changes in major selenium-containing compounds during thermal processing and storage. The results showed that selenomethionine (SeMet) is the predominant species in selenium-rich bean sprouts, and its stability is closely related to the redox enzymes in the bean sprout system. During processing or storage, SeMet is readily oxidized by reactive oxygen species into selenomethionine selenium oxides (SeMetO). However, SeMetO can be thermally reduced back to SeMet upon heating, revealing the reason for the stability of SeMet after processing. Additionally, the study elucidated the reduction kinetic equation of SeMetO, calculated its activation energy as 120.73 kJ·mol^-1, and clarified the impact of coexisting proteins, cellulose, and other components on the reduction process. This research provides an important theoretical basis for the processing of SeMet in selenium-rich foods.