Effect of wheat pearling on flour phytase activity, phytic acid, iron, and zinc content

This study examined the effect of wheat pearling on distribution of phytase, phytic acid, iron, and zinc in wheat fractions derived from pearling and roller milling. Grains of four wheat varieties were first pearled by a rice polisher at four levels, i.e. non-pearling (unpearled), 5% pearling (∼5% of the original sample weight was pearled), 10% pearling, and 15% pearling, to produce pearling fines (PF) and pearled grains. The unpearled and pearled grains were then milled through a Bühler MLU-202 laboratory mill, producing eight milling fractions. Results showed that pearling had a positive effect on flour yield, which may be attributed to the reduced yield of coarse bran and the improved yield of first and second reduction fractions. PF had high levels of all the four components, indicating that they could be a valuable source of iron and zinc. In addition, the differences between flours from the pearled and unpearled wheat were slight in terms of these four components.