Selenium in commercial beer and losses in the brewing process from wheat to beer

There is increasing interest in enhancing the micronutrient composition of cereals through fertilization. The aims of this study were (1) to determine the Se concentration of commercial beers retailing in the UK, and (2) to test if the transfer of Se, from biofortified grain to final beer product, is <10% under UK cultivation conditions, as seen previously under Mediterranean conditions. The Se concentration of 128 commercial beers was measured, using inductively coupled plasma-mass spectrometry (ICP-MS). The selenium content of commercial beers varied 6.5-fold, with beers originating from America having higher Se concentrations than those from Europe. Laboratory-scale brewing trials with isotopically-enriched (77)Se wheat, sampled from UK field-sites, showed that most (77)Se losses in the brewing process occurred during mashing (54%), with fermented beer containing ∼ 10% of the (77)Se initially present in the wheat grain. Total N values in wort and malt were positively correlated with the (77)Se content of the wheat grain.