Evaluating dietary exposure and risk characterization of aflatoxin B1, citrinin, and ochratoxin A co-occurrence in pigmented rice consumed in Thailand

In recent years, pigmented rice, often referred to as functional rice, has attracted increasing attention due to its perceived health benefits arising from an abundance of phytochemicals. However, there is limited information on the occurrence and risks of mycotoxins due to long-term consumption of pigmented rice. This study assessed the co-occurrence and contamination levels of aflatoxins, citrinin (CIT), and ochratoxin A (OTA) in various pigmented rice samples sourced from Thailand, and also evaluated the potential health risks for consumers. The results indicated varying levels of mycotoxin contamination among the different tested pigmented rice varieties, with aflatoxin B1 (AFB1) being the most prevalent (39.1 %), followed by CIT (17.3 %) and OTA (14.5 %). The co-occurrences of AFB1-CIT and CIT-OTA were the most prevalent combination observed in the pigmented rice samples. Although the AFB1 and CIT levels remained below regulatory limits, some samples had OTA levels exceeding these limits, though by a small percentage. Furthermore, the anthocyanin content in pigmented rice showed a weak positive correlation with the AFB1 level (p < 0.05). The estimated risk of liver cancer incidence associated with the consumption of pigmented rice containing AFB1 was in the range 0.012–0.061 cases/100,000 persons/year, depending on consumption rate and behavior. The risk posed by CIT exposure was considered negligible. However, the exposure assessments suggested a potential risk of OTA exposure, particularly in scenarios with higher consumption rates. Cumulative risk assessment of AFB1-OTA co-occurrence indicated an amplified health risk compared to single mycotoxin exposure. These findings offer valuable evidence, encouraging further research aimed at mitigating the risks associated with mycotoxin contamination in pigmented rice.