Adsorption of aflatoxin B1 by different antimycotoxin additives: bentonite, clinoptilolite, and beta-glucans extracted from yeast cell wall

The present study aims to evaluate and compare antimycotoxin additives (AMAs) composed of bentonite (AMA 1), clinoptilolite (AMA 2), and beta-glucans extracted from yeast cell wall (AMA 3), with respect to their ability to bind Aflatoxin B1 (AFB1) using the isothermal models of Freundlich, Langmuir, and BET. The additives were submitted to an in vitro adsorption experiment with AFB1 (0.05-4 mg L-1), using solutions of pH 3 and pH 6, with an inclusion rate of 0.5%, and analyzed by HPLC-MS/MS. At pH 3, for the seven concentrations evaluated, AMA 1 obtained adsorption rates (99.69 to 99.98%) higher (p < 0. 05) than the other AMAs, which were from 82.97 to 88.72% (AMA 2) and from 79.43 to 89.32% (AMA 3). At pH 6, in concentrations of 1, 2, and 4 mg L-1 of AFB1, AMA 1 obtained higher (p < 0.05) adsorption results (97.86 to 99.86%) than AMA 2 (91.98 to 96.12%) and AMA 3 (87.56 to 93.50%). The Freundlich model best fitted the AMA 1 adsorption data. For the other additives, the Langmuir model obtained the best fit, demonstrating qm of 8.6 mg g(-1) at pH 3 and 2.3 mg g(-1) at pH 6 for AMA 2; and for AMA 3, with q(m) of 3.4 mg g(-1) at pH 3 and 2.3 mg g(-1) at pH 6. The isotherm models work as an effective tool to describe the adsorption process whereas the AMA adsorption capacity varies as a function of product composition, pH, and mycotoxin content.

Automated summary

The present study evaluates and compares the ability of antimycotoxin additives to bind Aflatoxin B1. The results show that bentonite, clinoptilolite, and beta-glucans have different adsorption rates, with bentonite achieving higher rates at both pH 3 and pH 6.