Natural occurrence of fumonisins B1 and B2 in maize from three main maize-producing provinces in China

Fumonisins (FBs) mainly produced by some Fusarium species, such as Fusarium verticillioides and Fusarium proliferatum, are worldwide occurring in maize. Fumonisin B1 (FB1) and Fumonisin B2 (FB2) are the most abundant and the most toxic among all the known fumonisins. The fumonisins contamination of maize has raised serious economics, food safety and human health problems. The aim of this study was to determine the incidence and contamination levels of fumonisins in maize from different areas in China. A total of 146 samples of maize were collected in 2012 after maize harvest from three provinces including Gansu, Sichuan and Guizhou in China and analyzed for FB1 and FB2 using high-performance liquid chromatography coupled with fluorescence detection following o-phthalaldehyde derivatization. The results showed that the incidence and mean levels of fumonisins (FB1 + FB2) contamination for all collected maize samples were 39.7% and 497 ng/g, respectively. Among the three provinces, the mean level of total fumonisins contamination of maize samples from Guizhou province was 754 ng/g, which was higher than that of Sichuan (527 ng/g) and Gansu (202 ng/g). 3.4% of all maize samples had total fumonisins levels higher than 2000 ng/g set by the Food and Drug Administration of the United States and 1.4% had the levels in excess of 4000 ng/g recommended by the European Commission. The possible level of fumonisins exposure for the consumers (0.08 μg/kg of body weight per day) is within the provisional maximum tolerable daily intake of 2.0 μg/kg of body weight per day set up by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Nevertheless, more efforts should be made to prevent and control fumonisins contamination of maize and to minimize the potential risk to health of the consumers.