Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/1995
Publication Date: N/A
Interpretive Summary: Substances called tocols found in barley and other grains are important vitamins, having been shown to lower cholesterol in the blood and possibly helping to alleviate certain cancers. This study was conducted to find out what happens to the tocols when barley is processed for human food or malted and brewed for beer. It was found that in the milling of barley for pearled barley, a substantial portion of the tocols are removed. They are enriched in the "by- product" which might be incorporated into foods. During brewing, the tocols are concentrated in the brewers' spent grains, and these also, could be used in food applications. Marketing either the milling by-product or brewers' spent grains for human consumption would enhance their value, as compared to animal feed.
Technical Abstract: Barley (Hordeum vulgare L.) tocols were analyzed in products resulting from milling, malting and brewing to measure their concentrations in products that are or could be consumed by humans. Tocols in hand-dissected kernel fractions were also measured to explain the results with the milled fractions. Tocols were extracted with methanol and measured by fluorescence detection following high performance liquid chromatography. Removal of the hull, aleurone and germ by abrasion (pearling) significantly lowered the tocol concentration of the pearled barley as compared to whole kernels, but the by-product (material removed) was rich in tocols. Barley hulls and endosperm had substantial tocol concentrations, especially tocotrienols, whereas the germ contained a high concentration of alpha- tocopherol. Significant quantities of beta-tocotrienol were also found in the germ. Malting had essentially no effect on tocol concentration, but brewers' spent grains were enriched in tocols. It was concluded that high tocol concentrations of milling by-product and brewers' spent grains could make these valuable additions to food products.