Co-occurrence of aflatoxins B₁, B₂, G₁ and G₂, ochratoxin A, zearalenone, deoxynivalenol, and citreoviridin in rice in Brazil

Abstract

A total of 230 samples of processed rice and its sub-products or derived products were analysed to establish the co-occurrence of several mycotoxins. Samples were analysed in the period 2007–2009 due to the outbreak of beriberi associated with the consumption of rice stored in inappropriate conditions in Brazil. According to data from the Ministry of Health, 323 cases of disease were registered in 2006, of which at least 47 cases resulted in death. The occurrence of total aflatoxin (AFT) (aflatoxin B₁ + B₂ + G₁ + G₂), ochratoxin A (OTA), zearalenone (ZON), deoxynivalenol (DON), and citreoviridin (CTV) was 58.7%, 40.0%, 45.2%, 8.3% and 22.5%, respectively. From 166 rice samples analysed, 55% had levels <0.11 µg kg⁻¹ for AFT. For OTA and ZON, of 165 rice samples analysed, 28% and 29% were contaminated with levels from 0.20 to 0.24 µg kg⁻¹ and from 3.6 to 290.0 µg kg⁻¹, respectively. One sample (0.6%) was contaminated with 4872.0 µg kg⁻¹ of ZON. A total of 91% of rice samples (n = 165) did not contain detectable DON (<30.00 µg kg⁻¹), although the highest level of contamination was found to be 244 µg kg⁻¹. From the total of 65 samples analysed, 94% had no detectable CTV (<0.9 µg kg⁻¹), with a range from 0.9 to 31.1 µg kg⁻¹ in 6% of the samples. The highest levels of contamination were found in rice sub-products or derived products from the husk and rice bran. Co-occurrence was observed for AFT and ZON in 17.0%, AFT and OTA in 24.2%, AFT and CTV in 6.2%, OTA and CTV in 4.6%, and ZON and CTV in 3.1%. These fractions were also the major contributors for the co-occurrence. The results found show the necessity of monitoring rice production.

Keywords:

• chromatography – HPLC
• mycotoxins
• rice