Concentrations of elements in wheat grains grown in Australia, North America, and the United Kingdom

Abstract

Concentrations of elemental nitrogen, phosphorus (P), potassium (K), magnesium (Mg), sulfur, calcium (Ca), manganese (Mn), zinc, sodium (Na), boron, copper (Cu), and iron were compared in 47 samples of wheat grain collected from 17 grain terminals and a commercial flour mill in Australia and 38 samples of wheat obtained from a range of sites in North America and the U.K. The Australian samples included grain from the Prime Hard, Australian Hard, Australian Standard White, Australian Soft, and Durum grades, while the overseas samples included wheat of Hard Red Winter, Hard Red Spring, Soft Red Winter, Soft White Winter, Western White, and Canadian Red Spring grades. The Australian wheats, with the exception of 1 sample of Durum, contained less P, K, Mg, and Cu, but more Na, than most of the wheats grown overseas. The concentrations of P, K, Mg, Ca, and Mn in wheats grown overseas appear to have declined since earlier surveys were conducted. The relations between elements suggest that the amount of P deposited in the grain determines the concentrations of other elements, especially Mg and K. The P data presented in this study indicate that Australian wheats contain only 59-77% as much phytic acid as white and red wheats grown overseas. The claim that Australian wheats contain little Na compared with wheat from America is refuted. Consumers of unleavened, wholemeal products may be less likely to suffer nutritional imbalances if they use Australian wheat.