Occurrence and exposure assessment of aflatoxins in cocoa-derived products marketed in Spain

Aflatoxins (AFs) are potent carcinogenic mycotoxins of global concern, particularly in widely consumed cocoa-derived products. This study evaluated AFB1, AFB2, AFG1, and AFG2 in 394 samples (109 cocoa powder, 160 dark, and 125 milk chocolate bars) sold in Spain using a validated HPLC-FLD method. The method showed recoveries of 79.6-102.4%, with limits of detection (LOD) and quantification (LOQ) of 0.01-0.04 μg/kg and 0.03-0.12 μg/kg, respectively. AFs were detected in 51.4% of cocoa powder and 28.8% of chocolate bars. Dark chocolate had higher positivity (39.4%) than milk chocolate (15.2%). AFB1 was the most prevalent toxin, found in 43.1% of cocoa powder (mean 0.30 μg/kg). The highest AFB1 and AFG1 concentrations were in cocoa powder (up to 3.0 μg/kg and 3.3 μg/kg, respectively). A strong positive correlation was found between cocoa solids content and AF levels in cocoa powder. Risk assessment via the Margin of Exposure (MOE) showed potential health concerns for adolescents, children, and toddlers from average consumption of cocoa powder (MOE <10,000). Under high intake scenarios, all age groups showed concern. Although chocolate is a minor source, exposure in vulnerable high-consumers supports the need for continued monitoring and refinement of risk assessment at the European level.