Selenium in Se-enriched tartary buckwheat (Fagopyrum tataricum L. Gaertn.): Its molecular form and changes during processing

The essential trace mineral, selenium (Se), is of fundamental importance to human health. Tartary buckwheat is a pseudocereal variety rich in functional flavonoids. To investigate the characters of Se-enriched Tartary buck-wheat in Shaanxi province, we studied effect of different processing methods on its nutrients and selenium distribution in Se-enriched buckwheat groat (Se-BG), milled flour (Se-BMF), extruded flake (Se-BEF) and roasted groat (Se-BRG). The highest total selenium content in Se-BG was 118.04 mu g/kg. Se-BMF (110.55 mu g/kg) and Se-BEF (98.55 mu g/kg) showed less selenium loss while the most selenium loss was recorded in Se-BRG (66.63 mu g/kg). Selenium and selenomethionine (SeMet) were mainly present in glutelin, followed by albumin. SeMet content followed the trends of Se-BG (76.21 mu g/kg groat) > Se-BMF (75.24 mu g/kg groat) > Se-BEF (64.76 mu g/kg groat) > Se-BRG (21.21 mu g/kg groat).This shows that processing also has a great influence on the distribution of selenium forms.