Szymczykowska et al. 2026 — Elemental composition of Japanese matcha powder and infusions
This study analyzed the macro- and microelemental profiles of two organic Japanese matcha types — daily matcha (DM, second-to-third harvest) and traditional matcha (TM, first-to-second harvest) — from the Uji region of Kyoto, both in powder form and as infusions prepared at 25, 70, 80, and 90 °C, using ICP-OES. Brewing temperature had no statistically significant effect on elemental content in either infusion type, while infusion type (daily versus traditional) showed significant differences only for Ca, Na (higher in DM) and K, Ni (higher in TM). The study concludes that matcha infusions and powders are not significant sources of heavy elements under the applicable EU regulatory limits, specifically citing that Pb concentrations in all tested products fell within the permissible range under EU Regulation 2023/915.
Key numbers
Exact tabular data for this paper are reported in supplementary tables (S1–S4) and boxplot figures, which are not reproduced in the text-extracted version. The following quantitative anchors are available from the prose:
Elemental ranking patterns in matcha infusions (daily and traditional, all temperatures combined):
- Daily matcha infusion order: K > P > Mg > Ca > Na > Mn > Zn > Cu > Sr > Fe > Ni > Pb > Cr (mg/L)
- Traditional matcha infusion order: K > P > Mg > Ca > Mn > Na > Zn > Cu > Fe > Sr > Ni > Pb > Cr (mg/L)
- Matcha powder order (daily): K > Ca > P > Mg > Mn > Na > Fe > Zn > Cu > Sr > Cr > Ni (mg/kg); no Ni detected in powder
- Matcha powder order (traditional): K > P > Ca > Mg > Mn > Na > Fe > Zn > Cu > Sr > Cr > Ni (mg/kg); no Ni detected in powder
Lead: Detected in both infusions and powder. The paper states all tested products are safe with respect to Pb under EU Regulation 2023/915, which sets permissible Pb in plant products at 0.050–0.9 mg/kg depending on product type. No exact Pb values are stated numerically in the text; they appear in boxplots (Figure 1) not reproduced here. Comparison with Kolackova et al. (2020), the only prior matcha powder study, confirms analogous Pb findings.
Nickel: Present in both types of matcha infusion (statistically significant difference: TM higher than DM), absent in powder (attributed to matrix/analytical effects rather than true absence; discussed as cautionary finding). The paper states Ni concentrations correspond to approximately 0.9–1.1% of EFSA’s TDI (13 µg/kg body weight/day) per 100 mL serving for a 70 kg adult.
Chromium: Detected in both infusions and powder. Positioned last in the elemental ranking for infusions, indicating the lowest concentration among detected elements. No Cr speciation performed; values represent total Cr.
Manganese: Notable dietary contributor from matcha infusion — a 100 mL cup provides approximately 40% of the AI (adequate intake) of 2.3 mg/day for men and approximately 50% for women. This is the largest single-nutrient contribution from matcha among elements studied.
Brewing temperature: No statistically significant effect on any element concentration was observed across 25, 70, 80, or 90 °C. The authors attribute this to the fine suspension nature of matcha (maximized surface area leading to rapid equilibration).
Methods (brief)
ICP-OES (iCAP 7400, Thermo Fisher Scientific). Microwave digestion (MARS 5 CEM, 180 °C). Internal standard: yttrium (Y) at 0.5 mg/L; recovery 90–106%. R² values for all standard curves 0.998–1.000. Infusions prepared at 1.75 g matcha per 100 mL distilled water, 10 min at 180 rpm, filtered. Powder separately digested. Elements measured: Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Zn. Al was not measured. Arsenic, Cd, tAs, iAs, tHg, Sn, and U were not measured. Validated against NIST SRM 8414. Sample scope: two certified organic matcha products from a single region (Uji, Japan) and single producer; limited generalizability.
Implications
Certification: This paper covers Pb, Cr (total), and Ni in matcha but not Cd, As, Al, Sn, or Hg — the incomplete analyte coverage limits its use as a standalone HMT&C evidence source for matcha. For a category where whole-leaf suspension is consumed (higher exposure than steeped infusion), Cd and iAs data are the gaps most urgently needed. EU 2023/915 compliance is confirmed for Pb by the authors, but exact values require supplementary table access. Al is notably absent from this study despite tea being an Al hyperaccumulator; Al data must come from other sources (e.g., ozturk2024-al-tea-infusion-teapot).
Courses: Critical matcha-specific teaching point: because matcha is consumed as a whole-leaf suspension rather than a filtered infusion, consumers receive the full elemental load of the powder, not just the water-soluble fraction. Elemental concentrations in matcha powder are therefore the relevant exposure basis for most analytes, not infusion concentrations.
App: Matcha is a distinct ingredient from steeped green tea for exposure modeling purposes. The consumed form (whole powder as suspension) means powder concentrations are the correct input for the app’s risk model, not diluted infusion values. Dry powder Pb and Cr values are not numerically recoverable from this text extraction; supplementary tables S1–S4 in the MDPI online supplement contain exact figures.
Microbiome: Not addressed in this paper.