Sabri et al. 2025 — Essential and toxic elements in five spices from Greater Casablanca, Morocco

Sabri and colleagues at Hassan II University of Casablanca quantified five essential elements (K, Ca, Mg, Na, Fe) and five toxic trace metals (Pb, Cd, total As, Cr, Ni) by microwave-assisted ICP-MS in 137 bulk samples of cinnamon, cumin, turmeric, black pepper, and ginger collected from markets in the Greater Casablanca region, Morocco, between February and June 2025. Cinnamon stood out as the most contaminated spice on toxic metals: mean Pb 2.05 ± 0.23 mg/kg (range 1.228–2.4 mg/kg) exceeded the EU 2021/1317 limit of 2.00 mg/kg for bark-derived spices, and mean Cd 0.29 ± 0.07 mg/kg (range 0.157–0.394 mg/kg) exceeded the EU 0.20 mg/kg limit for dried spices. Cumin showed the highest total arsenic (0.45 ± 0.30 mg/kg) and nickel (4.18 ± 2.85 mg/kg) among the five spices but remained within EU caps where defined. Black pepper, ginger, and turmeric Pb and Cd values fell below their applicable EU thresholds. Principal component analysis on the ten-element profile separated cumin (driven by macro-elements Mg, Na, Ca) and cinnamon (driven by Cd and Pb) into distinct clusters; Pb and Cd correlated strongly (Pearson r = 0.87), which the authors interpret as evidence of a shared anthropogenic contamination source.

Key numbers

Sample design (Table 1)

The percentage column is internally inconsistent with the sample count: 37/162 = 22.8 % and 25/162 = 15.4 %, so the percentages are computed against a denominator of 162, which is also the figure stated in the abstract. The “Number of samples” column itself sums to 137, which the body text repeats. This wiki captures the per-spice n values from Table 1 (37, 25, 25, 25, 25) because those are the n’s that anchor the per-spice mean ± SD values in Tables 3 and 4; the 137 vs 162 discrepancy is recorded in the Verification notes for downstream awareness.

Toxic elements (Table 3), in mg/kg dry weight

Three black-pepper ranges in Table 3 (Pb, tAs, Ni) cannot contain their reported means and SDs — for example, the Pb mean of 0.60 mg/kg falls below the printed minimum of 0.818 mg/kg. The means are internally consistent with the body-text discussion, which uses the same figures (e.g. “the Pb content was 0.60 ± 0.24 mg/kg”). This wiki preserves both as printed and flags the apparent transcription error in the ranges in the Verification notes. The means are the authoritative summary statistics; the ranges for black pepper Pb, tAs, and Ni should not be relied on without re-derivation from the underlying data.

Macro-elements (Table 4)

Regulatory comparisons stated in the source

• EU Regulation 2021/1317 Pb limits for spices, as cited in the source: 2.00 mg/kg bark-derived spices, 1.50 mg/kg roots/rhizomes, 0.90 mg/kg seeds, 0.60 mg/kg fruit spices. Cinnamon Pb (2.05 mg/kg) marginally exceeds the bark limit. Black pepper Pb (0.60 mg/kg) is exactly at the fruit-spice limit. Cumin Pb (0.30 mg/kg) is below the seed limit. Ginger (0.15) and turmeric (0.14) are well below the rhizome limit (1.50).
• EU Regulation 2021/1323 (cited as the source for Cd 0.20 mg/kg in dried herbs, adjusted for spices using the European Spice Association dehydration factor). Cinnamon Cd (0.29 mg/kg) exceeds this limit.
• Codex Alimentarius Pb proposed limit for cinnamon, as cited: 2.50 mg/kg. Cinnamon Pb (2.05 mg/kg) is below the Codex proposal.
• No EU or Codex maximum limits for As, Cr, or Ni in spices are in force at the time of the study; the authors compare As values against an informal 0.2 mg/kg benchmark used in cereal/vegetable risk assessment.

Correlations and PCA

• Pearson r between Pb and Cd: 0.87 (strong positive, indicative of shared contamination source per the authors).
• Other notable correlations: Mg–Na r = 0.76; Ca–As r = 0.60; Mg–Ca r = 0.60; Ni–Na r = 0.63; Ni–Ca r = 0.51.
• Notable negative correlations: Cd–K r = −0.57, Pb–K r = −0.62, Pb–Mg r = −0.35, Cd–Mg r = −0.30. The authors discuss potential K-fertilisation antagonism on Cd uptake in plants.
• PCA Dim 1 (41.2 % variance) is loaded on Mg, Na, As, Ni, Ca and separates cumin (high macro-elements) from the rest. Dim 2 (23.4 % variance) is loaded on Cd, Pb, K, Ca and isolates cinnamon (high toxic metals). Cumulative variance on the first two components: 64.6 %.

Methods (brief)

• Sample matrix: 137 bulk spice samples from local markets in Greater Casablanca, purchased February–June 2025. Samples were stored in clean sealed containers at room temperature.
• Sample preparation in triplicate: 1 g of each spice digested in a Milestone microwave system (PTFE vessels, 110 bar maximum) with 5 mL HNO₃ 70 % + 2 mL H₂O₂ 30–32 %. Programmed heating: 80 °C/5 min → 120 °C/5 min → 150 °C/5 min → 180 °C/20 min → cool to 40 °C. Digests brought to 50 mL with ultrapure water. Method follows a modified AOAC International (2013) protocol.
• Analysis by Agilent ICP-MS with Fassel-type plasma torch (2.5 mm internal diameter), 1.5 kW forward power, 15 L/min plasma gas, 0.8 L/min auxiliary gas, 1.06 L/min nebuliser gas, 2 °C spray chamber. ASX-520 autosampler (Cetac Technologies). Daily tuning with Elan 6100 DRC solution (Perkin-Elmer Pure).
• Reagents: HNO₃ 70 % and H₂O₂ 30–32 % (Merck, Darmstadt). Ultrapure water (Milli-Q Plus, 18.2 MΩ·cm). Stock standards of Cr, Ni, As, Cd, Pb (10 µg/mL in 2 % HNO₃) and K, Ca, Na, Mg, Fe (10 000 µg/mL in 5 % HNO₃) from Agilent.
• Method validation: linearity R² 0.9989 (Ca) – 0.9999 (Mg, Ni); RSD 1.7 % (K) – 3.1 % (Pb); spike recoveries 91.43 % (K) – 105.12 % (Pb). LOQs (µg/L): K 57.2, Ca 21.4, Mg 0.350, Na 0.318, Fe 0.0793, Pb 0.0250, Cd 0.0030, As 0.0078, Cr 0.0522, Ni 0.1980.
• Quality control: IAEA-407 (fish homogenate) and NIST SRM 1570a spinach leaves as certified reference materials; control blanks; containers soaked in 10 % v/v HNO₃ ≥24 h and rinsed with Milli-Q before use.
• Statistics: R 4.3.2; Kaiser-Meyer-Olkin index for sampling adequacy (overall KMO = 0.80 in the discussion, 0.797 in Table 5); Bartlett’s test of sphericity (χ² = 153.42, df = 45, p < 0.001); PCA on the correlation matrix; Pearson correlations; Ward’s-linkage hierarchical cluster analysis. Significance threshold p < 0.05.
• Limitations relevant to wiki use: arsenic is total As (no iAs/oAs speciation); chromium is total Cr (no Cr-VI/Cr-III speciation); mercury was not measured; sample identifiers (brand, supplier, geographic origin within Morocco) are not disclosed; only spot bulk samples from one urban region.

Implications

Certification: Cinnamon is the row to watch on Pb and Cd in this dataset — both means cross EU 2021/1317 (Pb, bark spices 2.00 mg/kg) and EU 2021/1323 (Cd, dried-spice-adjusted 0.20 mg/kg). The Greater Casablanca cinnamon mean of 2.05 ± 0.23 mg/kg Pb sits at the EU bark-spice limit with a wide enough SD that a substantial share of individual samples can be expected to exceed it; whether that signal is supply-chain-specific or regionally representative needs additional sources before any threshold use. Cumin’s elevated total As (0.45 mg/kg) is worth flagging as a watchout because no operative EU or Codex spice cap is yet defined, and inorganic-As speciation is not available from this study.

Courses: Useful as a regional-market case study on multi-element ICP-MS profiling of bulk spices, on the PCA/correlation pattern that flags cinnamon as a Pb-and-Cd co-contaminated bark commodity, and on the limits of total-As reporting when speciation is needed for health risk inference.

App: Contributes occurrence values for cinnamon (Pb, Cd), cumin (tAs, Ni, Cr), ginger (Cr, Ni), black pepper (Cr, Pb), and turmeric (low across the panel). For the consumer estimator, Greater-Casablanca-sourced cinnamon is the highest-impact spice line for Pb and Cd exposure. Treat as one regional market dataset until cross-region sources accumulate.

Wiki pages updated on ingest

• cinnamon
• cumin
• turmeric
• ginger
• black-pepper
• spices
• lead
• cadmium
• arsenic-total
• chromium
• nickel

Verification notes

• Sample-count discrepancy (paper-internal). The abstract states “A total of 162 spice samples were obtained from markets in the Greater Casablanca, Morocco.” Table 1 states “A total of 137 bulk spice samples available on the market were collected” and the Number-of-samples column sums to 137 (37+25+25+25+25). The Percentage column in Table 1 (22.8 % / 15.4 % × 4) is computed against a denominator of 162 (37/162 = 22.8 %, 25/162 = 15.4 %), so two different totals are in use within the same paper. This wiki uses 137 as the bulk-sample total and the per-spice n values (37 for cinnamon, 25 each for cumin/turmeric/black pepper/ginger) from Table 1 because those are the values that anchor the mean ± SD entries in Tables 3 and 4 referenced throughout the discussion. The discrepancy is a paper-side defect; it cannot be reconciled from the PDF alone.
• Black-pepper range columns in Table 3 appear miscoded. The printed ranges for Pb (0.818–0.96), tAs (0.401–0.493), and Ni (0.648–0.952) in the black-pepper row do not contain their corresponding mean ± SD values (Pb 0.60 ± 0.24, tAs 0.27 ± 0.14, Ni 0.45 ± 0.26). The means are internally consistent with the body-text discussion (which explicitly states “the Pb content was 0.60 ± 0.24 mg/kg”) and with the EU-fruit-spice-limit comparison the authors make. The black-pepper Cr (0.899–6.583, mean 3.62 ± 2.13) and Cd (0.006–0.049, mean 0.03 ± 0.01) ranges are consistent. This wiki carries the means as the authoritative summary statistics and labels the affected ranges “as printed” so downstream synthesis does not silently propagate the inconsistency.
• Total arsenic, total chromium, no mercury. The five toxic elements are reported as total concentrations. There is no inorganic-As / organic-As speciation, no Cr-VI / Cr-III speciation, and no mercury measurement (neither tHg nor MeHg). For any HMI analyte requiring speciation, this paper is a tAs and total-Cr source only.
• No geographic-origin metadata within Morocco. Samples are described as bulk market spices in Greater Casablanca; the paper does not record country/region of cultivation, supplier identity, organic vs conventional status, or harvest year. Geographic-variance entries in downstream ingredient pages should treat this as one Greater-Casablanca-market dataset.
• License terms. Scienceline Publication (publisher of World’s Veterinary Journal) operates open-access journals, but the PDF does not carry an explicit CC licence statement. Treat as open-access cite-and-link until the journal’s terms are confirmed.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.