Comparative efficacy of agricultural by-products in sequestering mycotoxins

BACKGROUND: Biosorption using agricultural by-products has been proven as a low-cost and safe way to sequester mycotoxins. Few agricultural by-products have been studied for their efficacy in adsorbing simultaneously a large range of mycotoxins. The present work compared the ability of 51 agricultural by-products to adsorb mycotoxins from liquid mediums simulating physiological pH values, and it studied the mechanism for mycotoxin adsorption by isotherm adsorption experiments. RESULTS: Grape pomaces, artichoke wastes, and almond hulls were selected as promising biosorbents for mycotoxins, being quite effective towards aflatoxinB1 (AFB1), zearalenone (ZEA), and ochratoxinA (OTA). Their adsorption was not affected by medium pH, and the adsorbed fraction was not released when pH rose from acid to neutral values. FumonisinB1 (FB1) was adsorbed to a lesser extent, and deoxynivalenol adsorption was not recorded. For the selected biosorbents, maximum adsorption capacity calculated by the best fittingmodel (Freundlich, Langmuir, or Sips equation) ranged from 1.2 to 2.9 µg mg-1 for AFB1, 1.3 to 2.7 µg mg-1 for ZEA, 0.03 from 2.9 µg mg-1 for OTA , and 0.01-1.1 µg mg-1 for FB1. CONCLUSION: This study confirms that someagricultural by-products can find technological applications as feed/food additives for mycotoxin reduction.