Occurrence of aflatoxins in organic rice produced and commercialized in Brazil

Abstract

Since rice is one of the most important cereals for the human diet worldwide, and its organic production has increased over the last years, the objective of this study was to evaluate the occurrence of aflatoxins in samples of organic rice produced and sold in Brazil, and to determine the average probable daily intake (APDI) of aflatoxins due to the consumption of organic rice. Sixty samples were analyzed for aflatoxins B₁, B₂, G₁, and G₂ using high-performance liquid chromatography (HPLC). Results demonstrated that 8.3% of brown rice samples showed levels from 0.13 to 1.24 μg/kg considering the sum of aflatoxins B₁, B₂, G₁, and G₂, while one sample (8.33%) of polished rice and one sample (33.34%) of red rice presented levels of 0.11 μg/kg and 0.16 μg/kg for AFB₁ and AFG₂, respectively. According to the Factor Analysis of Mixed Data (FAMD), AFB₁ and AFG₁ had the highest occurrence in samples, and the rice type was the qualitative variable with the greatest intensity, showing that the rice manufacturing process can influence the levels of aflatoxins found in grains. The APDI value was 0.004 μg/kg b.w./day for the sum of aflatoxins B₁, B₂, G₁, and G₂, indicating that daily consumption of contaminated rice may pose a risk of hepatocarcinogenicity. Although the concentrations of aflatoxins found in the present study did not exceed the maximum tolerable limit recommended by Brazilian regulations (5 μg/kg for cereals), additional studies are necessary to obtain a vast database for the occurrence of aflatoxins in organic rice and, thus, to establish new tolerable limits avoiding risks for consumer health.