New hepatocarcinogen, fumonisins : food contamination and the distribution of fumonishin-producing fungi

采用高效液相色谱法，对日本、尼泊尔、中国、泰国、马来西亚等国的玉米及玉米基产品中伏马菌素B1和B2的天然存在进行了研究。在9个进口玉米粒和6个面筋饲料样品中，8个玉米样品(0.6-4.1个/g)和所有面筋饲料样品(0.3-2.4个/g)中检出伏马菌素B1，而同一批玉米(0.3-10.2个/g)和3个面筋蛋白饲料(0.8-8.5个/g)样品中检出伏马菌素B2。酶联免疫吸附分析还发现，2个玉米和所有面筋饲料样品中的黄曲霉毒素B1与伏马菌素一起受到污染。在17份玉米粒样品中，伏马菌素B1污染14份，B2污染5份，最高污染水平分别为2.6和2.8µg/g。至于在日本出售的以玉米为原料的食品，则没有发现有严重的伏马菌素污染。尼泊尔24份玉米粒样品中，伏马菌素B1和B2阳性分别为12份和7份，平均分别为0.6和1.6µg/g。同一样品中最高含量分别为4.6和5.5µg/g。在上海和北京的中国收获的玉米样品中，检测到不同浓度的伏马菌素B1和B2。泰国的样本伏马菌素B1和B2的水平分别为0.3至1.8和0.1至0.4微克/克。在马来西亚，少数样本伏马菌素B1和B2呈阳性。真菌学调查显示，在日本的一块农田中存在产生伏马菌素的真菌。这些发现首次证明了亚洲地区玉米和玉米基产品中存在高水平的伏马菌素污染。在混合饲料原料中也检测到伏马菌素和黄曲霉毒素B1的天然共存。

Natural occurrence of fumonisin B1 and B2, a promoter for hepatocarci nogenesis, was investigated in corn and corn-based products sampled in Japan, Nepal, China, Thailand and Malaysia by high-performance liquid chromatographic method. In 9 imported corn kernel and 6 gluten feed samples, fumonisin B1 was detected in 8 corn (0.6-4.1 mug/g) and all gluten feed (0.3-2.4 mug/g) samples, while fumonisin B2 was found in the same corn (0.3-10.2 mug/g) and 3 gluten feed (0.8-8.5 mug/g) samples. ELISA analysis also revealed the contamination of aflatoxin B1 in 2 corn and all gluten feed samples along with fumonisins. In 17 samples of corn grits, 14 and 5 samples were contaminated with fumonisin B1 and B2, with the maximum levels of 2.6 and 2.8 mug/g, respectively. As for corn-based foodstuffs marketed in Japan, no significant contamination of fumonisins was observed. Among 24 samples of corn kernels in Nepal, 12 and 7 samples were positive for fumonishin B1 and B2, and averaged to 0.6 and 1.6 mug/g, respectively. The maximal contents were counted to 4.6 and 5.5 mug/g in one same sample respectively. In corn samples harvested at Shanghai and Beijing in China, fumonisin B1 and B2 were detected in various concentrations. Thailand samples were positive for fumonisin B1 and B2 at levels ranging from 0.3 to 1.8 and 0.1 to 0.4 mug/g, respectively. In Malaysia, a few samples were positive for fumonisin B1 and B2. Mycological survey has revealed the presence of fumonisin-producing fungus in a crop field in Japan. These findings have firstly demonstrated the contamination of fumonisins with high levels in corn and corn-based products in Asian contries. Natural co-occurrence of fumonisins and aflatoxin B1 was also detected in raw materials for mixed feed.