Overview
Ghasemi and colleagues collected dough and baked bread of three wheat bread types from traditional and industrial bakeries across Mashhad in late 2020. They measured twelve elements by ICP-OES on a dry-weight basis and compared dough with bread and traditional with industrial ovens. Lead and mercury were below detection in every sample.
Key numbers
- Lead and mercury: lower than the detection limit in all samples (Results, p. 107).
- Baked bread cadmium: 0.027 ± 0.02 mg/kg (traditional ovens) vs 0.023 ± 0.01 mg/kg (industrial ovens), p = 0.004 (Table 2, p. 109).
- Baked bread arsenic: 0.49 ± 0.16 (traditional) and 0.46 ± 0.13 mg/kg (industrial) (Table 2); overall 0.479 ± 0.229 mg/kg (Abstract).
- Aluminum: 3.21 ± 1.23 (traditional) vs 3.77 ± 1.32 mg/kg (industrial) (Table 2).
Methods (brief)
Samples were oven-dried at 100 °C, digested with nitric and hydrochloric acids by microwave (EPA 3050B) and read by ICP-OES. Detection limits are printed in µg/L of solution. A rice flour reference material and spikes gave 87 to 112% recovery.
Evidence Fitness
Peer review is unverified: the PDF prints received and accepted dates but no review record was seen. The DOI printed in the PDF was not in the manifest and was not checked against Crossref. Sample counts per table cell are unclear and one Table 1 cell is malformed. Arsenic near 0.5 mg/kg by ICP-OES is high for wheat bread. Values are for yeast flatbreads, a proxy for flour-tortilla, butter-crackers, graham-crackers and cinnamon-roll; those pages are not linked.