Post-harvest operations and aflatoxin levels in rice (Oryza sativa)

• Stationary drying resulted in higher aflatoxin contamination.
• Bran showed higher aflatoxin contamination.
• Intermittent drying is recommended, due to less contamination with aflatoxins.

This study evaluated the effect of post-harvest operations on the occurrence of aflatoxins in rice (Oryza sativa) samples. Newly harvested rice was subjected to stationary, intermittent, or combined drying, and stored in concrete storehouses during 10 months. The aflatoxins were extracted with methanol: potassium chloride and quantified by HPLC-FL. After ten months of storage, the highest aflatoxin levels were found in rice bran, of which the values were above 25 μg/kg for the sum of the aflatoxins (B1 + B2 + G1 + G2). The rice fractions of the endosperm and husk from the intermittent drying showed the lowest aflatoxin levels during the storage.