Improved MethodofScreening forAflatoxin witha Coconut AgarMediumt

rapidly andeconomically. Suchscreening differs fromprograms whichsurvey agricultural commodities, mixedfeeds, and rawandprocessed foodsforcontamination withaflatoxin (4-6, 8)inthatourinterest isintheaflatoxin-producing potential oftheisolated spores rather thantheamountof aflatoxin perseinagiven substrate. Inthis regard, wefound thescreening methods described previously tobeunsuitable forourpurposes. De Vogeletal.(3)described a screening testwitha complex agarmediumcontaining sucrose, various salts, and anaqueous extract ofaflatoxin-free groundnuts (peanuts). A thin layer ofHyflo Supercel wasspread onthebottom ofthe dishbefore themediumwaspoured into plates. Following inoculation andincubation for48to72h,plates were examined underUV radiation (350 to370nm),andabright bluefluorescence indicated thepresence ofaflatoxin. Hara etal.(5)described asomewhat similar methodthat didnot require thegroundnut extract. Theyusedamodified Czapek agarmediumcontaining cornsteep liquor, namedaflatoxinproducing-ability (APA)medium.APA mediumwasless laborious toprepare thantheDe Vogeletal.medium. However, wehavefound that after prolonged storage, corn steep liquor maylose its aflatoxin-promoting