Pankavec et al. 2019 — Mineral constituents of commercially pickled white button mushrooms (Poland)
This study characterised the multi-element composition of commercially conserved white button mushrooms (Agaricus bisporus) available on the Polish market, measuring 23 elements including the toxicologically critical analytes Hg, As, Cd, Pb, Ni, Al, Cr, Sb, Tl, and U across 100 packages from 10 product batches from six manufacturers. The central finding is that industrial pickling substantially reduces concentrations of toxic metals relative to fresh mushrooms: pickled A. bisporus contained median Pb of 0.072 mg/kg dry mass (dm), Cd 0.040 mg/kg dm, Hg 0.043 mg/kg dm, and As 0.030 mg/kg dm — all well below the EU limits of 0.30 mg/kg dm for Pb and 0.20 mg/kg dm for Cd. Significant inter-producer variability was observed for several elements, particularly Li, As, Rb, Sr, Ag, Ba, and Cs, which the authors attribute to differences in marinade quality rather than mushroom substrate, consistent with principal component analysis findings.
Key numbers
All values reported as mg/kg dry mass (dm), assuming approximately 90% moisture content in fresh mushrooms; EU limits apply to fresh weight (fw): 0.30 mg/kg fw for Pb = 3.0 mg/kg dm; 0.20 mg/kg fw for Cd = 2.0 mg/kg dm.
Overall median values across all 10 batches (Table 2):
| Element | Overall median (mg/kg dm) | Range of per-batch medians |
|---|---|---|
| As (total) | 0.030 | 0.006–0.19 |
| Hg (total) | 0.043 | 0.028–0.065 |
| Cd | 0.040 | 0.020–0.080 |
| Pb | 0.072 | 0.006–0.18 |
| Ag | 0.020 | 0.002–0.090 |
| Sb | 0.015 (approx.) | variable per batch |
| Tl | 0.001–0.002 (approx.) | below detection in some batches |
| U | 0.001 | 0.0004–0.003 |
| Ni | 1.0 | 0.10–1.1 |
| Al | 2.8 | 1.4–24 |
| Cr | 0.20 | 0.071–0.88 |
| Se | 0.60 | 0.19–1.6 |
| Co | 0.015 | 0.004–0.02 |
Batch 1 (Notre Jardin sliced) showed statistically elevated Li, As, Rb, Sr, Ag, Cs, Ba (PC1, 42% of variance) — interpreted as marinade-quality contribution, not substrate contamination. Batch 9 (Ole natural marinade, whole) showed elevated Se, Cr, Zn. Batches 5 and 7 had relatively elevated Cd and Hg (PC5).
Comparison with fresh A. bisporus: fresh mushrooms in Poland showed Cd 0.36 ± 0.47 mg/kg dm, Pb 0.54 ± 0.54 mg/kg dm, Hg 0.069–0.11 mg/kg dm — roughly an order of magnitude higher than in pickled product for Cd and Pb, and approximately 1.5–2x higher for Hg. As in fresh A. bisporus (Poland): 0.63 ± 0.37 mg/kg dm, vs < 0.05 mg/kg dm detected in pickled (sliced and whole) — roughly a 10-fold reduction, attributed to water-soluble arsenical species (arsenobetaine, monomethylarsonic acid, etc.) leaching during blanching and pickling.
Aluminum showed the widest inter-batch variability (1.4 to 24 mg/kg dm), with the highest Al batch attributed to marinade quality (Al is not efficiently leached from mushrooms during marinating).
EU regulatory reference: Commission Regulation (EC) No 629/2008 amending 1881/2006 sets Cd ≤ 0.20 mg/kg fw and Pb ≤ 0.30 mg/kg fw for cultivated Agaricus bisporus. All batches in this study were well below these limits.
Methods
ICP-MS DRC (PE Sciex ELAN 6100 DRC II) for 20 elements including As, Cd, Pb, Ni, Al, Cr, U, Sb, Tl; CV-AAS (MA-2000, Nippon Instruments) for Hg. Samples from 10 product batches representing 6 manufacturers; 80 packages in glass jars, 20 (Bonduelle) in cans. Lyophilised and ground to fine powder before microwave acid digestion (65% HNO3, PTFE vessels, CEM MARSXpress). QA/QC using Polish reference materials CS-M-2 (Agaricus campestris) and CS-M-3 (Boletus edulis). PCA (Statistica v8.0, Varimax rotation) on 18 elements and 10 batches. Methods validated per earlier publications by the same group. Published in Roczniki PZH (Annals of National Institute of Hygiene), a peer-reviewed public health journal indexed in major databases.
Basis: dry mass. Moisture content assumed approximately 90% for conversion to fresh-weight regulatory comparisons.
Implications
Certification: Conserved/pickled mushrooms are a low-risk product for Pb, Cd, Hg, and As relative to EU limits. The pickling process itself functions as a decontamination step (10-fold reduction in As, substantial reductions in Pb and Cd versus fresh). The source of inter-batch variability lies in marinade quality (water, vinegar, salt mineral content), not primarily in mushroom substrate. Brands sourcing from sub-optimal marinade ingredients may show elevated Li, Rb, Cs, As, and Al.
Courses: Strong illustration of how food processing (industrial pickling) materially changes heavy metal risk profiles. Also illustrates the substrate vs. marinade sourcing question as a quality-control lever for conserved mushroom products.
App: Pickled/conserved mushrooms can be assigned low-risk contamination profiles for Pb, Cd, Hg, and As based on this study. Inter-producer variability (up to ~10x for some elements within-batch) means lot-level variation is real and relevant. Al is the highest-concentration contaminant and is driven by marinade quality.
Microbiome: Not addressed in this source.