Overview
Khmeleva and colleagues summarized lead, nickel, mercury, copper, zinc and cadmium in 30 batches of wheat grown in the Orel region from 2015 to 2018. They then tested whether steeping grain with enzyme preparations, as in whole grain bread making, lowers lead, nickel, zinc and copper. This short conference paper is in an IOP proceedings volume.
Key numbers
- Wheat grain lead by harvest year: 0.125 (2015), 0.12 (2016), 0.28 (2017), 0.32 mg/kg (2018); cadmium 0.01 to 0.025 mg/kg (Table 1, p. 2).
- Wheat grain mercury: 0.004 to 0.06 mg/kg; nickel 0.19 to 0.66 mg/kg (Table 1).
- Steeping with a cellulolytic enzyme complex and then washing: lead 0.059 mg/kg vs 0.187 mg/kg in the washed control and 0.256 mg/kg in the unwashed control (Table 2, p. 3).
Methods (brief)
Table 1 gives averaged values; its analytical method and per-year counts are not stated. In the steeping trial, grain was soaked 18 hours at 35 to 40 °C and pH 4.5 to 5.0 with one of four commercial enzyme preparations, washed or not, dried, and analyzed by HPLC peak area. No detection limits, reference materials or recoveries are reported.
Evidence Fitness
A short conference paper with little method detail. Measuring metals by HPLC is unusual and is not validated here. The text’s 99% nickel reduction does not match its own Table 2. Raw wheat grain is an ingredient proxy for bagel and toaster-pastry; those pages are not linked. The steeping results are mitigation evidence for whole grain bread processing.