# Assessment of Cheese Contamination and Its Contribution to Aflatoxin M1 Intake in the Spanish Population

**Authors:** Susana Lorán, Marta Herrera, Agustín Ariño, Teresa Juan

PMC · DOI: 10.3390/foods15040720 · 2026-02-15

## TL;DR

This study assesses AFM1 contamination in Spanish cheeses and its impact on public health, finding low risk for most age groups except toddlers.

## Contribution

The study provides new data on AFM1 levels in Spanish cheeses and evaluates dietary exposure for different age groups.

## Key findings

- AFM1 was detected in 51% of 100 cheese samples, with concentrations ranging from 8.1 to 470.7 ng/kg.
- Cheeses made from cow's milk and pasteurized milk showed higher contamination rates.
- Dietary exposure estimates were low for most age groups, with toddlers showing the highest risk.

## Abstract

Global concern surrounds the contamination of dairy products with aflatoxin M1 (AFM1), a mycotoxin found in the milk of ruminants fed with aflatoxin B1-contaminated feed. Among dairy products, cheese is of the foods with the highest concentration of AFM1 mycotoxin, although the reported levels vary widely. This study analyzed AFM1 levels in 100 commercial cheeses produced and marketed in Spain. AFM1 was detected in 51% of the samples, with concentrations ranging from 8.1 to 470.7 ng/kg. The milk type and animal species significantly influenced the contamination levels with a higher prevalence and mean contamination rates in cheeses made from cow’s milk (67.6% and 43 ng/kg) and pasteurized milk (60.7% and 33 ng/kg). The degree of ripening of the cheese did not significantly influence the contamination of the products, although the occurrence and average levels observed in fresh cheeses (63.0% and 53 ng/kg) were higher than those observed in mature (48.0% and 13 ng/kg) and semi-mature cheeses (43.5% and 11 ng/kg). There were no significant differences in the contamination levels between artisanal (56.6% and 33 ng/kg) and industrial (44.7% and 12 ng/kg) cheeses. The dietary exposure estimates for average consumers were low across all age groups: 0.004 ng/kg bw/day (adults), 0.007 ng/kg bw/day (adolescents), 0.025 ng/kg bw/day (children), and 0.081 ng/kg bw/day (toddlers). Consequently, the Margin of Exposure (MOE) values exceeded 10,000, indicating a low public health concern, except for toddlers in the 95th percentile of consumption.

## Linked entities

- **Chemicals:** aflatoxin M1 (PubChem CID 15558498), aflatoxin B1 (PubChem CID 186907)

## Full-text entities

- **Diseases:** carcinogenic (MESH:D011230), toxicity (MESH:D064420), injury to (MESH:D014947), Cancer (MESH:D009369)
- **Chemicals:** lipids (MESH:D008055), calcium (MESH:D002118), AFM1 (MESH:D016607), AFB2 (-), Aflatoxins (MESH:D000348), water (MESH:D014867), formic acid (MESH:C030544), methanol (MESH:D000432), sodium chloride (MESH:D012965), AFB1 (MESH:D016604), acetonitrile (MESH:C032159), lactose (MESH:D007785), Lactic acid (MESH:D019344)
- **Species:** Bos taurus (bovine, species) [taxon 9913], Capra hircus (domestic goat, species) [taxon 9925], Aspergillus flavus (species) [taxon 5059], Aspergillus nomiae (species) [taxon 41061], Homo sapiens (human, species) [taxon 9606], Ovis aries (domestic sheep, species) [taxon 9940], A. flavus [taxon 315677], Aspergillus parasiticus (species) [taxon 5067], Meleagris gallopavo (common turkey, species) [taxon 9103], Altererythrobacter sp. FM1 (species) [taxon 2484537]

## Figures

1 figure with captions in the complete paper: https://tomesphere.com/paper/PMC12939574/full.md

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Source: https://tomesphere.com/paper/PMC12939574