Wheat selenium

Meltzer HM, Norheim G, Loken EB, et al. 1992. Supplementation with wheat selenium induces a dose-dependent response in serum and urine of a Se-replete population. Br J Nutr 67(2) 287-294. 

Owing to low levels of selenium in the blood serum of the population of Finland, at the beginning of the 1980s it was decided to increase the selenium content in food crops by the addition of sodium selenate to the fertilisers used (the doses were 6-16 mg of selenium per kg of fertiliser). In a few years (from 1984-1986), the content of selenium in important crops and livestock products had increased. For example, wheat selenium content increased from 0.01 to 0.23, in potatoes from <0.002 to 0.02, in milk from 0.008 to 0.03 and in e s from 0.16 to 0.31 mg/kg. The average daily dose of dietary selenium increased to about 90 pg, and the selenium concentration in breast milk increased from 0.007 to 0.015 mg/kg. 

Soltanpour P.N., Olsen S.R., Goos R. J. Effects of nitrogen fertilization of dryland wheat on grain selenium concentration. Soil Sci Soc Am J 1982 46 430-433. 

Selenium is an essential trace element for optimal health but an excess is toxic. The British population is now reckoned to be selenium deficient because more European wheat is now used to make bread at the expense of North American wheat. The difference in the selenium content is caused by the difference in the selenium content of the soils. In geological terms, European soil is older and the selenium has washed out. 

Day-old mallard ducklings fed diets for 2 weeks containing 0, 15, or 30 mg Se/kg ration in a 75% wheat diet (22% protein). Selenium given as seleno-DL-methionine, seleno-L-methionine, or selenized yeast... 

Heinz, G.H., D.J. Hoffman, and L.J. LeCaptain. 1996. Toxicity of seleno-L-methionine, seleno-DL-methionine, high selenium wheat, and selenized yeast to mallard ducklings. Arch. Environ. Contamin. Toxicol. 30 93-99. 

In terms of human dietary requirements, much of the wheat for breadmaking in the United States is produced in selenium-adequate sections of the country. Bread is generally a good source of dietary selenium, Selenomethionine decomposes lipid peroxides and inhibits in vivo lipid peroxidation in tissues of vitamin-E-deficient chicks. Selenocysdne catalyzes the decomposition of organic hydroperoxides. Selenoproteins show a high degree of inhibition of lipid peroxidation in livers of sheep, chickens, and rats, Thus, some forms of selenium exhibit in vivo antioxidant behavior,... 

Detection limits range from 0.02ng/ml for arsenic to 0.80ng/ml for selenium, and precision values at lOng/ml are less than 6% relative standard deviation. Results of analyses of NBS standard reference materials (wheat flour, rice flour, spinach and orchard leaves) demonstrate the application of the method to the matrices. The layout of the apparatus is illustrated in Fig. 7.6. 

Djusic, I.S., Djermanovic, V., and Milovac, M. 1998. Foliar supplementation with selenium the efficient way to increase Se content in wheat grain, its products and human consumers. In Proc. 6th Internat. Symp. Uses of Selenium and Tellurium (Y. Palmieri, ed.), pp. 129—134, Scottsdale, AZ. Grimbergen. 

Hurd-Karrer, A.M. 1934. Selenium injury to wheat plants and its inhibition by sulphur. J. Agric. Res. 49, 343-357. 

C. Brunori, M. B. de la Calle, M. Angelone, R. Morabito, Determination of total selenium in mussel and wheat samples after tetramethylammonium hydroxide digestion, Ann. Chim., 89 (1999), 873D880. 

E. J. Gawalko, T. W. Nowicki, J. Babb, R. Tkachuk, Comparison of closed-vessel and focused open-vessel microwave dissolution for determination of cadmium, copper, lead, and selenium in wheat, wheat products, corn bran, and rice flour by transverse-heated graphite furnace atom, Int. J. Assoc. Off. Anal. Chem., 80 (1997), 379-387. 

V. Diaz Huerta, L. Hinojosa Reyes, J. M. Marchante-Gay n, M. L. Fernandez Sanchez, A. Sanz-Medel, Total determination and quantitative speciation analysis of selenium in yeast and wheat Bour by isotope dilution analysis ICP MS, J. Anal. Atom. Spectrom., 10 (2003), 1243D1247. 

Hawkesford, M.J. and Zhao, F.-J. 2007. Strategies for increasing the selenium content of wheat. Journal of Cereal Science, 46 282-92. 

Lyons, G., Stangoulis, J., and Graham, R. 2003. High-selenium wheat Biofortification for better health. Nutrition Research Reviews, 16 45-60. 

Robinson, W.O., 1933. The determination of selenium in wheat and soils. J. Assoc. Offic. Agric. Chem., 16 423—424. 

Se-enriched plants may be divided into two broad groups [199], i.e. selenium accumulators and/or selenium non-accumulators. Selenium-accumulating plants can be divided into three subgroups selenite-accumulators (broccoli and cucumber), selenomethionine accumulators (grains such as wheat, and mushrooms) and iS e-methyl selenomethionine accumulators (garlic and onion) [200]. 

Selenium enters the food chain mainly as selenomethionine from plants that take the element up from the soil but do not appear to use it. The soil content of selenium is highly variable and can be low in volcanic soils when soluble salts are leached out by ground water. Soils in parts of China and New Zealand are particularly low in selenium. Acid soils, where insoluble selenium complexes can be formed with iron and aluminum, occur in some parts of Europe, resulting in low available soil selenium. The geographical source of plant and animal foodstuffs determines the level of dietary intake. In the United States and Canada, wheat and other cereal products are a good source of selenium average intakes in North America range from 80 to 220 fig Se per day, whereas in the UK dietary intake is about 30 to 60 Llg/day. Intakes in China are as low as 11 lg/day and in New Zealand 28 fig/day. ... 

Schroeder and Mitchener (1972). Halverson et al. (1966) reported reduced liver-to-body-weight ratios and increased bilirubin in rats administered 0.44 mg selenium/kg/day for 6 weeks as naturally occurring selenium in wheat. At this level, five of eight rats died. At a dose of 0.84 mg selenium/kg/day administered as sodium selenate in drinking water for 4-6 weeks, rats developed cirrhosis of the liver (Palmer and Olson 1974). At this level, two of six rats died. 

Increased serum bile acids, suggesting cholestasis, were observed in rats treated with 1.57 mg selenium/kg/day as sodium selenate in drinking water for 13 weeks, but no effects were noted at 0.92 mg/kg/day (NTP 1994). In a 13-week drinking water study, hepatic effects were not observed in mice treated with sodium selenate at 7.17 mg selenium/kg/day, in mice treated with sodium selenite at doses up to 3.83 mg selenium/kg/day, or in rats treated with sodium selenite at doses up to 1.67 mg selenium/kg/day (NTP 1994). Increased serum aspartate aminotransferase and alanine aminotransferase activities were observed in mice treated by gavage with selenocystine at doses of 9.4 mg selenium/kg/day for 30 days (Sayato et al. 1993) or 4.7 mg selenium/kg/day for 90 days (Hasegawa et al. 1994). No effects on liver enzymes were observed in mice treated with selenocystine at 4.7 mg selenium/kg/day for 30 days (Sayato et al. 1993) or at 2.5 mg selenium/kg/day for 90 days (Hasegawa et al. 1994). Chronic dietary administration of selenium as seleniferous com or wheat at doses ranging from 0.25 to 0.50 mg/kg/day for 24 months produced cirrhosis of the liver in rats (Nelson et al. 1943). 

Lambs given a single oral (subroute not specified) dose of 5 mg selenium/kg as sodium selenite exhibited cytoplasmic flocculation of the pancreas (Smyth et al. 1990). Increased pancreas weights were observed in rats fed organic selenium (seleniferous wheat) at a dose of 0.4 mg selenium/kg/day for 6 weeks (Halverson et al. 1966). Chronic exposure of rats fed sodium selenite or sodium selenate in their diet for a lifetime was associated with pancreatic damage. Although Harr et al. (1967) reported a dose-related increase in the incidence and severity of pancreatic lesions in treated rats, they did not specify the lowest dose at which pancreatic lesions were observed. 

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