The aim of research was to test the capability of glucomannan yeast product (GYP) and glucomannan resulted from Amorphophallus oncophyllus extraction (GRE) to bind aflatoxin in in vitro testing. Before in vitro testing, both GYP and GRE were analyzed to determine proximate analysis, glucose, and mannose concentrations. In vitro testing used aflatoxin, binder and gastro intestinal fluid in 3% ringer solution. The weights of binders were 41.05; 82.1; 123.15; and 164.2 mg and weight of aflatoxin was 0.1642 µg of each tube. The results showed that the percentage of aflatoxin bound increased by the increasing weight either glucomannan from yeast product or glucomannan resulted from A. oncophylus extraction. The percentages of aflatoxin binding with binder of both glucomannan yeast product were 19.72%; 21.51%; 42.25%; 46.35% and glucomannan from A. oncophyllus extraction were 4.08%; 28.72%; 36.73%; and 89.07%, consecutively. There were positive correlations (
