CHAPTER 11: Bioavailability of Selenium and Selenium Compounds in Foodstuff by In Vitro Testing

Although in vivo human studies are the ultimate test to determine the bioavailability of an essential/toxic substance in foodstuffs, and that in vivo animal reflects the real situation; some of these experimental approaches are ethically controversial. As an alternative, bioavailability can also be estimated through various in vitro methods. An overview on in vitro bioavailability assays for releasing selenium and selenium species in food samples is summarized. Theoretical and practical aspects of in vitro approaches are described. Several in vitro static (including Caco-2 cell model) and dynamic models (simulator of the human intestinal microbial ecosystem model, SHIME) applied to selenium bioavailability assessment are commented. The effect of food composition; and heat treatment and curing/ripening, canned, fermentation and aging processes of food on the selenium species bioavailability during in vitro processes is also critically evaluated. Finally, selenium species stability/species transformation during in vitro processes are also described.