Studies on the Fluorescent Compounds in Fermented Foods

Part 2.Test on Aflatoxin Contamination of Miso and Miso-koji in Japan

Abstract

Studies were made to investigate whether miso and miso-koji (a solid culture of industrial koji-mold strain on rice)in Japan contained aflatoxins or not.1080f the commercial miso, 33 of home made miso and 28 of miso-koji from almost all the prefectures of Japan were tested for their aflatoxin contamination and toxicity by the methods of thin-layer chromatography, liquid chromatography, UV absorption and chicken embryo bioassay (yolk sac test). As the results of aflatoxin contamination test, no aflatoxin was detected from any of them. But on the thin-layer chromatograms, 3 commercial misos, one home made miso and 2 miso-kojis showed aflatoxinlike fluorescent substances. The extracts of these aflatoxin-like substances were examjned by yolk sac test for their toxicity to chicken embryo. The results however were all negative.