Simultaneous Removal of Mycotoxins by a New Feed Additive Containing a Tri-Octahedral Smectite Mixed with Lignocellulose

Abstract

Simultaneous removal of mycotoxins has been poorly addressed, and a limited number of studies have reported the efficacy of feed additives in sequestering a large spectrum of mycotoxins. In this study, a new mycotoxin-adsorbing agent was obtained by properly mixing a tri-octahedral smectite with a lignocellulose-based material. At a dosage of 1 mg mL−1, these materials simultaneously adsorbed frequently occurring mycotoxins and did not exert a cytotoxic effect on intestinal cells. Chyme samples obtained by a simulated GI digestion did not affect the viability of Caco-2TC7 cells as measured by the MTT test. In addition, the chyme of the lignocellulose showed a high content of polyphenols (210 mg mL−1 catechin equivalent) and good antioxidant activity. The properties of the individual constituents were maintained in the final composite, and were unaffected by their combination. When tested with a pool of seven mycotoxins at 1 µg mL−1 each and pH 5, the composite (5 mg mL−1) simultaneously sequestered AFB1 (95%), FB1 (99%), ZEA (93%), OTA (80%), T-2 (63%), and DON (22%). HT-2 adsorption did not occur. Mycotoxin adsorption increased exponentially as dosage increased, and occurred at physiological pH values. AFB1, ZEA and T-2 adsorption was not affected by pH in the range 3–9, whereas OTA and FB1 were adsorbed at pH values of 3–5. The adsorbed amount of AFB1, ZEA and T-2 was not released when pH rose from 3 to 7. FB1 and OTA desorption was less than 38%. Langmuir adsorption isotherms revealed high capacity and affinity for adsorption of the target mycotoxins. Results of this study are promising and show the potential of the new composite to remove mycotoxins in practical scenarios where several mycotoxins can co-occur.