Eighty-five commercial premade baby foods from Coimbra, Portugal, were dry-ashed and measured for nickel by graphite furnace atomic absorption. Nickel was above the 12.5 μg/kg method detection limit in 78 samples (91.8%), with an average of 40.4 μg/kg and a maximum of 225.7 μg/kg. Fruit jars had the highest group average (50.1 μg/kg), then ready meals (40.2), paps (32.4 in the results; 33.4 in the conclusions), and desserts (23.5). Products labelled organic averaged 54.7 μg/kg, higher than those not so labelled (35.8 μg/kg). Using average concentrations, the estimated daily intake for a 2-year-old eating these foods plus breast milk reached 3.13 μg/kg body weight when fruit was included, above the EFSA tolerable daily intake of 2.8 μg/kg body weight cited by the paper.
Key numbers
| Analyte | Matrix | Value | Unit | Statistic | N | Where |
|---|---|---|---|---|---|---|
| Ni | premade baby food method | 12.5 | μg/kg | lod | p.PDF p.1 | |
| Ni | natural mineral water MRL, as cited | 20 | μg/L | regulatory_limit | p.PDF p.2 (printed 2) | |
| Ni | WHO TDI | 11 | μg/kg body weight | regulatory_limit | p.PDF p.2 (printed 2) | |
| Ni | EFSA TDI | 2.8 | μg/kg body weight | regulatory_limit | p.PDF p.2 (printed 2) | |
| Ni | all premade baby foods | 40.4 | μg/kg | mean | 85 | p.PDF p.3 (printed 3) |
| Ni | all premade baby foods | 225.7 | μg/kg | max | 85 | p.PDF p.3 (printed 3) |
| Ni | fruits (jars) | 50.1 | μg/kg | mean | 31 | p.PDF p.3 (printed 3) |
| Ni | fruits (jars) | 225.7 | μg/kg | max | 31 | p.PDF p.3 (printed 3) |
| Ni | ready meals (jars) | 40.2 | μg/kg | mean | 26 | p.PDF p.3 (printed 3) |
| Ni | paps | 32.4 | μg/kg | mean | 20 | p.PDF p.3 (printed 3) |
| Ni | desserts (jars) | 23.5 | μg/kg | mean | 8 | p.PDF p.3 (printed 3) |
| Ni | paps, conclusions section | 33.4 | μg/kg | mean | 20 | p.PDF p.6 (printed 6) |
Methods (brief)
Half-MDL and half-MQL substitution was used for statistics. Kruskal-Wallis and Mann-Whitney tests. EDI assumed gastric capacity about 30 g/kg and body weights 8, 10.25, and 12.75 kg at 6 months, 1 year, and 2 years, with a diet of only these commercial foods plus breast milk. Worst-case EDI used the highest concentration in each food group; those maxima other than the overall and fruit maximum of 225.7 μg/kg are not printed in the main text.
Detection and reporting: MDL 12.5 μg/kg; MQL 38.0 μg/kg, from a matrix-matched curve on a nickel-free meat ready meal. Recoveries 78.0-90.1% at 100, 200, and 300 μg/kg. Values below MDL were replaced by half the MDL for statistics, and values between MDL and MQL by half the MQL.
Basis: Nickel in the product as analysed. The paper does not state dry versus wet weight. Comparisons with other studies treat jar foods on a wet or product basis. Not a migration test.
Evidence fitness
This source can support: Total Ni in Portuguese-market premade baby foods as group means and one maximum; Organic versus non-organic and private versus white-label averages; EDI compared with the cited EFSA TDI of 2.8 μg/kg body weight.
It cannot support: Sample-level concentrations; A dry-weight conversion; Other metals; A food MRL for nickel (the paper says none exists).
Limitations
Individual sample rows are in supplementary Table S4 and were not in this pdftotext file, so they were not transcribed. The paps average is 32.4 μg/kg in the results and 33.4 μg/kg in the conclusions; both are entered. Dry versus wet basis is not stated. Organic count is printed as 21 (31%) although 21 of 85 is not 31%; the count 21 is what was used. No nickel speciation. Brand names are discussed as private versus white label without a brand table.
Related evidence
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