Distribution of Cadmium, Iron, and Zinc in Millstreams of Hard Winter Wheat (Triticum aestivum L.)

Abstract

Hard winter wheat (Triticum aestivum L.) is a major crop in the Great Plains of the United States, and our previous work demonstrated that wheat genotypes vary for grain cadmium accumulation with some exceeding the CODEX standard (0.2 mg kg(-1)). Previous reports of cadmium distribution in flour milling fractions have not included high cadmium grain. This study measured the distribution of cadmium, zinc, and iron in flour and bran streams from high cadmium (0.352 mg kg(-1)) grain on a pilot mill that produced 12 flour and four bran streams. Recovery in flour was substantially greater for cadmium (50%) than for zinc (31%) or iron (22%). Cadmium, zinc, and iron in the lowest mineral concentration flour stream, representing the purest endosperm fraction, were 52, 22, and 11%, respectively, of initial grain concentration. Our results indicate that, relative to zinc and iron, a greater proportion of cadmium is stored in the endosperm, the source of white flour.

The effects of wheat cultivars on the production of different types of wheat flours of precisely defined magnesium content

“…The extraction of soluble minerals from flour fractions, shorts and bran from gained milling streams and whole grain of each grain cultivar was extracted with Tris-HCl buffer according to procedure described by Guttieri et al [18] with some minor modifications.…”

Contaminants in Grain—A Major Risk for Whole Grain Safety?

“…Toxic metals compete with other metals for the transport systems in the plant, which explains why they are taken up into the different compartments of the grain. For example, cadmium is stored in the endosperm of wheat, the source of refined flour and to a lesser extent in the outer layers of the grain [ 101 ]. Fungi often colonizes the outer layers of the grains but some can also infect, for example, corn kernels through slit channels.…”

Cadmium in soil, crops and resultant dietary exposure

“…The categories 'bran and germ' and 'wheat grains and flour' in the EFSA report (2009) have higher Cd concentrations (mean 0.06 and 0.03 mg/kg respectively), as compared to 'wheat products' (mean 0.014 mg/kg). Detailed research has found the highest Cd concentrations in bran and the pollard fractions and the lowest concentrations in wheat grain and flour (Oliver et al, 1993;Guttieri et al, 2015). However, a relation was found between the Cd in the different fractions: Cd concentrations in grains are an effective method to monitor the Cd concentrations in flour and flour products (Oliver et al, 1993).…”

“…In most countries, the varieties differ, which makes comparisons between countries less straightforward. It is also well-known that in non-polluted soils with a low pH (Great Plains of USA), some wheat genotypes (hard winter-wheat) can accumulate Cd in grains and exceed the European limit value (Guttieri et al, 2015).…”