Quantification and In Vitro Bioaccessibility of Selenium from Osborne Fractions of Selenium-Rich Cereal Grains

Cereal crops cultivated in the seleniferous belt of Punjab, India, were observed to hyperaccumulate a significantly high concentration of selenium (20-123 mu g/g). Selenium concentration (mu g/g) in storage proteins of wheat, maize, and rice, namely, albumin (401, 280, and 29, respectively), globulin (264, 192, and 242, respectively), glutelin (563, 359, and 178, respectively), and prolamin (629, 339, and 257, respectively) indicated variable selenium levels, with prolamin contributing significantly higher levels of selenium when compared with other proteins with reference to the total concentration of the protein fraction. The simulated gastric and gastrointestinal digestion studies indicated better accessibility of selenium during intestinal digestion, with variability across proteins and cereal types. The observations provide an insight into the bioavailability of selenium in selenium-rich cereal grains, used in the study, and their potential use as source for selenium supplementation to deficient populations, or as "bioactive" selenium-rich nutraceutical blends for health benefits.