Occurrence and Risk Characterization of Ochratoxin A in Commercial Cow's Milk From Markazi Province, Iran

ABSTRACT

Ochratoxin A (OTA) is a heat‐resistant mycotoxin with recognized nephrotoxic and carcinogenic effects. This study aimed to determine OTA occurrence in commercial milk marketed in Markazi Province, Iran, and to evaluate the associated health risks for consumers. A total of 180 cow's milk samples comprising raw ( n  = 60), pasteurized ( n  = 60; seven commercial brands), and UHT milk ( n  = 60; twelve commercial brands) were randomly collected across four seasons from retail outlets in Arak, Khomein, and Mahallat between October 2024 and 2025. All samples were analyzed using HPLC‐FLD. Dietary exposure was estimated for adults and children using the Estimated Daily Intake (EDI), and risk characterization was performed using the Margin of Exposure (MOE) approach. OTA was detected in 99.44% of samples, with an overall mean concentration of 57.99 ± 37.21 ng/kg. Raw milk showed the highest contamination levels, reaching 126.90 ng/kg in summer, whereas UHT milk exhibited the lowest concentrations (10.38 ng/kg in winter). Risk assessment revealed that MOE values for neoplastic effects in children consuming raw (4356) and pasteurized milk (7967) were below the safety threshold of 10,000, indicating potential carcinogenic concern. In contrast, MOE values for adults across all milk types remained within acceptable limit. The widespread detection of OTA suggests contamination within the regional feed supply chain. Given OTA's thermal stability, lower concentrations in industrially produced UHT milk likely reflect superior hygiene and quality‐control practices. These findings highlight the need for establishing national OTA limits in milk and improving feed storage and management to reduce exposure, particularly among children.