Cicero et al. 2022 — Mineral and microbiological analysis of spices and aromatic herbs

This Italian study simultaneously assessed microbiological contamination and trace mineral content in 13 dried spice and aromatic herb samples purchased from an international market in Saudi Arabia, representing products sourced from India, Iran, Indonesia, and Vietnam. Mineral analysis by ICP-MS (Agilent 7500CX) quantified 18 elements including all four potentially toxic metals (Cd, Pb, As, Hg) plus Al, Ni, Cr, Sn, V, Co, Sb, Sr, Fe, Mn, Cu, Se, Zn, and Be. Microbiological analyses confirmed the samples met EU criteria for food safety pathogens. For the four regulated heavy metals, Pb was the primary concern: ajwan seeds (thymol seeds) from India showed 0.544 mg/kg, five times the EU fresh herb limit of 0.1 mg/kg. Aluminium reached 930 mg/kg in thymol seeds and 145 mg/kg in saffron, representing notable accumulation. All Cd, As, and Hg values were within regulatory limits across all 13 samples.

Key numbers

Potentially toxic elements (Cd, Pb, As, Hg) across all 13 samples:

• Cd: range 0.003–0.079 mg/kg (all within EU MPL of 0.2 mg/kg)
• Pb: range 0.008–0.544 mg/kg; two samples above EU fresh herb limit of 0.1 mg/kg
  • Ajwan seeds (Trachyspermum ammi, India, sample L): 0.544 ± 0.003 mg/kg (p < 0.05 vs limit)
  • Saffron (Iran, sample E): 0.096 ± 0.005 mg/kg (close to limit, p > 0.05)
  • All others below 0.1 mg/kg: black pepper (Vietnam) 0.008, cinnamon (Indonesia) 0.023, organic fenugreek (India) 0.010, black cumin (India) 0.034, caraway (India) 0.043
• As (total): range 0.003–0.339 mg/kg (all within WHO limit of 5 mg/kg)
  • Thymol seeds (India, sample L): 0.339 ± 0.006 mg/kg (same sample with highest Pb)
  • Caraway (India): 0.078 ± 0.001 mg/kg
  • Saffron (Iran): 0.086 ± 0.002 mg/kg
• Hg (total): range 0.001–0.010 mg/kg (all well below WHO limit of 0.2 mg/kg and EU limit)

Aluminium:

• Thymol seeds (India, sample L): 930.198 ± 5.269 mg/kg — extremely high
• Saffron (Iran): 145.216 ± 6.281 mg/kg
• Caraway (India): 87.507 ± 0.269 mg/kg
• Chia seeds (Sabja, India, sample O): 46.889 ± 1.678 mg/kg
• Chia seeds (Iranian Tokhme Sharbati, Iran, sample B): 32.355 ± 0.008 mg/kg
• Other spices: 7–43 mg/kg (fenugreek 7.112, black cumin 19.963, coriander 19.914, clove buds 20.532, cinnamon 27.168, black sesame 32.508, black pepper 43.064; cress sprouting seeds 8.863)

Selected additional minerals:

• Cr: range 0.021–2.357 mg/kg; cinnamon (Indonesia) 2.357, thymol seeds 1.113
• Ni: range 0.416–3.053 mg/kg; black cumin (India) 3.053, cinnamon (Indonesia) 2.766
• Sn: range < LOD–2.392 mg/kg; coriander (India) 2.392, black pepper (Vietnam) 1.174
• Sr: range 4.299–95.917 mg/kg; caraway (India) 95.917, cinnamon (Indonesia) 50.586
• Contamination sequence: Pb > As > Cd > Hg

Microbiological results: Black cumin, Iranian chia seeds, and caraway showed elevated total coliform and Enterobacteriaceae counts (some above reference limits); all samples negative for Salmonella and L. monocytogenes; no foodborne pathogens detected.

Methods (brief)

ICP-MS (Agilent 7500CX with Octapole Reaction System) following microwave acid digestion (HNO3 + H2O2 at 1000 W, 180°C, 10 min hold). Internal standard: Re at 0.8 mg/L. Validated against NIST 1570A (spinach leaves); recoveries 93–103% for all elements except Hg (92.93%). LODs ranged from 0.001 to 0.051 µg/kg; LOQs from 0.003 to 0.168 µg/kg. All analyses in triplicate. Reports total arsenic and total mercury (no speciation). Study collected from Saudi Arabian international market — products represent supply chains destined for Europe and Middle East. Regulatory comparisons against EU Regulation EC 1881/2006 and amendments (EU 1317/2021 for Pb; EU 1323/2021 for Cd) and WHO guidelines.

Implications

Certification: Contributes occurrence data for 13 spice commodities sourced from India, Iran, Indonesia, and Vietnam. The 0.544 mg/kg Pb in ajwan/thymol seeds from India is reported at five times the EU fresh herb limit of 0.1 mg/kg; co-occurrence of the highest Pb and tAs values in the same sample is consistent with a soil-origin contamination pattern rather than adulteration. The 930 mg/kg Al value in the same thymol seeds sample is a notable accumulation outlier in this corpus.

Courses: Adds evidence that regulatory compliance on Cd, tAs, and tHg in a single survey does not, on its own, characterise Pb risk: this study reported all Cd/tAs/tHg values within EU/WHO limits but two Pb exceedances against the fresh-herb limit, both in less commonly studied spice categories (ajwan/thymol seeds, Abbaszadeh saffron). Also adds evidence on broad multi-element screening: several non-toxic but accumulation-relevant elements (Sr, Co, Sn) showed notable variation across spice types.

App: Provides ICP-MS data for 13 spice commodities across multiple metals. Thymol seeds and coriander are data points not well covered in other studies in this batch. Ajwan seeds Pb (0.544 mg/kg) and tAs (0.339 mg/kg) are notable for this commodity. Cinnamon from Indonesia shows Pb 0.023 mg/kg, Cd 0.071 mg/kg, Cr 2.357 mg/kg, Ni 2.766 mg/kg — less severe than Vietnamese/Indian cinnamon in other studies but adds geographic contrast.

Verification notes

2026-05-29 merge-enhance pass: re-read PDF Table 4(c) against page. Corrected aluminium attribution for chia seeds — the 46.889 ± 1.678 mg/kg value belongs to Sabja Seeds (sample O, India), not Iranian Tokhme Sharbati (sample B, Iran), which actually measured 32.355 ± 0.008 mg/kg. Both samples are Salvia hispanica (chia seeds) under different regional names; the paper text refers to “chia seeds” generically and the prior page version paired the wrong cultural label with the wrong country. Removed IT from jurisdictions: the lab is in Italy (University of Messina) but no samples represent Italian supply — samples were purchased in Saudi Arabia and originated in India, Iran, Indonesia, and Vietnam.

Paper-internal inconsistencies kept as paper-text values (lower than Table 4 minima): As range “0.003–0.339 mg/kg” matches paper §3.2.5 text although Table 4(c) shows G (black pepper) at 0.002; Hg range “0.001–0.010 mg/kg” matches paper text although Table 4(c) minimum is 0.002. These are paper-internal discrepancies between text and tables, not extraction errors.

Audit subagent (2026-05-29) verdict REVISE: numerical fidelity all ✅ (Table 4(c) chia-seeds aluminium re-attribution verified correct); slug vocabulary and speciation all ✅; brand firewall ✅; Part 2 wiki/HMTc firewall ⚠️ on three Implications phrasings — applied: replaced “HMT&C supplier assessment should include…” directive with occurrence-data contribution framing; replaced “warrants investigation” with neutral “notable accumulation outlier”; reframed Courses “does not guarantee clean supply” as descriptive Pb-vs-other-metal observation tied to the study’s own findings rather than cross-source synthesis. No false positives to reject.

Wiki pages updated on ingest

• herbs-and-spices
• cinnamon
• black-pepper

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