Overview
Golian and colleagues grew 59 oyster mushroom production strains on the same straw substrate and measured aluminum, barium, copper, iron, manganese, zinc and macro elements in caps and stipes by ICP-OES. A second trial fortified the substrate with sodium selenate and tracked nickel, cobalt, chromium, mercury and other elements. This is an experimental cultivation study, not a market survey.
Key numbers
- 59 strains, cap vs stipe: zinc 81 ± 25 vs 41 ± 15 mg/kg DM; copper 6.2 ± 1.5 vs 5.3 ± 2.4 mg/kg DM (Table 3).
- Highest cap zinc 920 mg/kg DM and highest cap copper 18.0 mg/kg DM in single strains (Table 5).
- Selenium trial, control vs 2.0 mg/dm3 Se: nickel 0.68 ± 0.32 vs 1.80 ± 0.24, mercury 0.041 ± 0.0041 vs 0.048 ± 0.0048, chromium 0.89 ± 0.52 vs 0.47 ± 0.17 mg/kg DM (Table 6).
Methods (brief)
Microwave nitric acid and hydrogen peroxide digestion; ICP-OES for most elements, AMA 254 for mercury and ET-AAS for selenium. LODs are listed in Table 2; NIST SRM 1570a recovery 95.2%.
Evidence Fitness
Experimental conditions on one substrate, so the values show strain and part effects rather than market levels. Lead and cadmium in Table 6 are credited to the authors’ earlier paper and are not extracted, and the 59-strain survey reports no toxic metals. Oyster mushrooms are a proxy for cream-of-mushroom-soup; the study does not support that page directly.