Bioavailable zinc in grains of bread wheat varieties of Pakistan

Abstract

Estimation of zinc and its bioavailability in wheat grains is a prerequisite for an effective biofortification program. The selected 65 bread wheat varieties are representative of indigenous and foreign genetic pools being used for genotype development at the Wheat Research Institute, Faisalabad (Pakistan). The main objectives of the study were: (i) to determine the variation in phytate and zinc concentrations in whole grains; (ii) to estimate the bioavailable zinc in wheat grains by using trivariate model of zinc absorption and phytate to zinc molar ratios ([phytate]:[zinc]); and (iii) to examine the interrelationship of bioavailable zinc with year of variety release. Average zinc in grains of wheat varieties was 29 μg g−1 and ranged from 24 to 36 μg g−1. Phytate in grains ranged from 7.1 to 11.1 mg g−1 resulting in a variation in [phytate]:[zinc] of 24 to 41. The estimated bioavailable zinc in grains ranged from 1.52 to 2.15 mg zinc for 300 g of wheat flour, indicating that only 21 ± 3% of grain zinc wa...