A limited survey of fumonisins in corn and corn-based products in Asian countries.

Natural occurrence of fumonisins B1 (FB1) and B2 (FB2), a promoter for hepato-carcinogenesis, was investigated in corn and corn - based products sampled in Japan, Nepal, and China by high - performance liquid chromatographic method. From the 9 imported corn kernel and 6 gluten feed samples, FB1 was detected in 8 corn (0.6 ∼ 4.1μg/g) and all gluten feed (0.3 ∼ 2.4μg/g) samples, while FB2 was found in the same corn (0.3 ∼ 10μg/g) and 3 gluten feed (0.8 ∼ 8.5μg/g) samples. ELISA analysis also revealed the contamination of aflatoxin B1 in 2 corn and all gluten feed samples along with fumonisins. Of 17 corn grit samples, 14 and 5 samples were contaminated with fumonisin B1 and B2, with maximum levels of 2.6 and 2.8μg/g, respectively. As for corn-based foodstuffs marketed in Japan, no significant contamination of fumonisins was observed. Among 24 corn kernel samples in Nepal, 12 and 7 samples were positive for FB1 and FB2, and averaged to 0.6 and 1.6μg/g, respectively. One sample showed the highest fumonisin contents as 4.6 and 5.5μg/g, respectively. In corn samples harvested at Shanghai and Beijing, China, FB1 and FB2 were detected in various concentrations. Mycological survey has also revealed the presence of a fumonisin - producing fungus in a crop field of Japan. These findings have for the first time demonstrated high levels of contamination of fumonisins in corn and corn - based products in Asian countries. Natural co - occurrence of fumonisins and aflatoxin B1 was also detected in raw materials for mixed feed.