Mineral and trace element composition of Wheat and wheat flours of different extraction rates

Abstract

Grain samples of hard, soft and durum wheat varieties grown under identical agroclimatic conditions and the samples of 70, 80, 90 and 100 per cent extraction flours of five hard wheat varieties were analysed for total ash, Ca, P, Mg, Fe, Zn, Cu, Mn, Mo and Cr contents. Varietal differences were significant for Zn, Mn, Mo and Cr in hard wheats and for Fe, Zn and Mo in durum wheats. In soft wheats varietal differences were not significant for any of the nutrients analysed. Significant positive correlations were observed between Cu and Cr, and both these elements in turn were positively correlated with Ca, Fe, Mn and Mo. Zn was significantly correlated with total ash, Mn and Mo; P with total ash and Mn, and Ca with Mn. Among the three types, durum wheats Were rich and hard wheats were poor in mineral and trace element content. In the wheat flours, lowering the rate of extraction resulted in the decrease in the concentration of all the nutrients. In the flour of 90 per cent extraction the relative losses ranged from 6.6 per cent in iron to 60 per cent in chromium ; in the flour of 80 per cent extraction, the losses were 16.1 per cent in calcium to 66 per cent in chromium and in the flour of 70 per cent extraction, 16.1 Per cent in calcium to 76 per cent in chromium.