Aflatoxin binders I: In vitro binding assay for aflatoxin B1 by several potential sequestering agents

Nine potential proprietary sequestering agents consisting of 4 activated charcoals, 3 sodium bentonites, a calcium bentonite, and an esterified glucomannan were compared in a novel in vitro assay for aflatoxin B1 (AFB1) binding. Agents were evaluated in 10% methanol prepared as 1% stirred suspensions at pH 3, 7, 10 and pH-unadjusted, with or without AFB1 at 5 mug/ml. All nine agents bound more than 95% of the 5 mug of AFB1 in solution, regardless of pH. The sodium bentonites bound 98, 95, and 98% of the AFB1. The four activated charcoals bound over 99%, the calcium bentonite bound 98%, and the esterified glucomannan bound 97% of the AFB1 in solution. The results suggested that the sequestering agents tested here had sufficient potential to bind AFB1 at pH values commonly found in the gastrointestinal tracts of ruminants and other animals.