Effect of Zn application methods on Zn distribution and bioavailability in wheat pearling fractions of two wheat genotypes

Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Five pearling fractions (representing approximately 20% of the original sample weight) of wheat grain were obtained using the JNMJ3 rice polisher for two cultivars with different methods of Zinc (Zn) application; the residual portion (approximately 80%) was ground as flour. Results showed that foliar or soil+foliar Zn application methods effectively increased Zn concentrations and bioavailability in whole grain and pearling fractions, but soil Zn application was ineffective in field conditions. In addition, the concentrations of Zn, Fe, Mn and Cu within wheat grain showed a diminishing trend from the outer layer to the inner portions of the wheat grain as the pearling level increased. These results clearly showed the distribution of minerals in wheat grain, especially in the outer part of the grain (bran). The results also suggest that precise milling techniques combined with foliar Zn application could improve the Zn and Fe nutritional qualities of consumed flour and mitigate human Zn and Fe deficiencies.