Activated Carbons: In Vitro Affinity for Ochratoxin A and Deoxynivalenol and Relation of Adsorption Ability to Physicochemical Parameters

Abstract

In vitro affinity tests were conducted to test the effectiveness of 19 activated carbons (ACs), hydrated sodium calcium aluminosilicate (HSCAS) and sepiolite (S) in binding ochratoxin A (OA) and deoxynivalenol (DON) from solution. Relationships between adsorption ability and physicochemical parameters of ACs (surface area, iodine number, methylene blue Index) were tested. When 5 ml of a 4-μg/ml aqueous solution of OA was treated with 2 mg of AC, the ACs adsorbed 0.80 to 99.86% of the OA. HSCAS and S were not effective in binding OA. In two saturation tests carried out with increased amounts of OA (5 ml of 10- and 50-μg/ml aqueous Solutions of OA, respectively), three ACs also showed high adsorption ability (adsorbing 92.23 to 96.57% of the OA). When 5 ml of a 4-μg/ml aqueous solution of DON was treated with 10 mg of AC, ACs adsored 1.83 to 98.93% of the DON. HSCAS and S were not effective in binding DON. An overall relation of adsorption ability to the physicochemical parameters of ACs was observed. The methylene blue index was more reliable than iodine number and surface area in predicting ability of ACs to adsorb OA and DON. Based on the data observed on the present study as well as on aflatoxin B1 and fumonisin B1 from previous studies, it is concluded that ACs have high in vitro affinity for chemically different mycotoxins, and can be considered as potential multi-mycotoxin-sequestering agents. However, the ability to bind the main mycotoxins singly or in combination should be confirmed by in vivo investigations. Moreover, information on the amounts of AC to be added to feeds, and on the possible long-term effect on absorption of essential nutrients are needed.