Adsorption of ochratoxin A, deoxynivalenol and zearalenonein vitro at different pH and adsorbents

The adsorption of standards of 100 µg/kg Ochratoxin A (OTA), 30 mg/kg Deoxynivalenol (DON) and 30 mg/kg Zearalenone (ZEA) from 2.5 ml phosphate buffer (pH 3.0 and pH 7.0) and pure destilled water were studiedin vitro after addition of 0.1, 0.25, 0.5, 1.0 and 2.5 % (w/v) activated charcoal and four adsorbents (A I-A IV). Adsorbent A I was 1.0, 2.5 and 5.0 % modified yeast cell wall+vitamin mixture+plant oil refined. A II was modified yeast cell wall. A III was bentonite+enzymes+modified yeast cell wall+vitamin E+trace elements. A IV was bentonite. The adsorption for OTA and ZEA were 100 % by 0.1 % activated charcoal, but DON adsorption ranged from 47 to 99 % depending on the concentration of charcoal and pH value. However, adsorption of DON by 0.5, 1.0 and 2.5 % charcoal did not differ significantly by different pH buffers. Adsorption of OTA by A I, A II and A III (1.0 and 2.5 %) was higher in pH 7.0 buffer and pure destilled water compared to pH 3.0 buffer. A IV and 5.0 % A II showed an opposite trend. However, adsorption of OTA was by A II>A III>A IV (at pH 7.0 and water). The overall means of adsorption were higher by A II>A III>A IV>A I. Generally, the adsorption ranged from 15 to 60 % depending on kind and concentration of adsorbents and pH values. DON adsorption (30, 16 and 5 mg/kg) was not affected by A I, A II, A III and A IV. Adsorption of ZEA was highest by A I, and the lowest by A III. The means of adsorption at different pH were by A I>A II>A IV (2.5 and 5.0 %)>A III. The overall means show the same trend. Generally, the adsorption ranged from 13 to 57 %.