Agriculture waste materials as potential mycotoxin adsorbents

In the field of animal protection, the use of adsorbent materials to decontaminate mycotoxin contaminated diets will become an effective strategy to counteract mycotoxin problems in animal production if these materials have the ability to bind combinations of mycotoxins. So far, most substances used as mycotoxin binders (in particular clays) fail in sequestering structurally different mycotoxins. This study examined the ability of 51 agricultural-by products to adsorb mycotoxins from liquid mediums simulating the pH values (3 and 7) that can be found in the GI tract of humans and monogastric animals. Mechanism of mycotoxin adsorption was studied by isotherm adsorption experiments. Grape pomaces, artichoke wastes, and almond hulls were selected as promising biosorbents, being quite effective towards AFB1, ZEA, and OTA. Their adsorption was not affected by medium pH, and the adsorbed fraction was not released when pH rose from acid to neutral values. FB1 was adsorbed to a lesser extent, while DON was not adsorbed. For selected agricultural by-products, maximum adsorption capacities calculated by the Freundlich, the Langmuir, and the Sips isotherms ranged from 1.2 to 2.9 µg/mg for AFB1, 1.3 to 2.7 µg/mg for ZEA, 0.03 to 2.9 µg/mg for OTA, and 0.01 to 1.1 µg/mg for FB1. In conclusion, this study shows that selected agricultural by-products can find technological applications as feed/food additives for mycotoxin reduction. They represent a low cost, and potentially valuable source of phenolic antioxidants and undegradable fibre, which can promote health also through their ability to "trap" mycotoxins in the digestive tract