In vitro Detoxification of Aflatoxin B1 by Calcium Bentonite Clay Supplementation in Aflatoxigenic Mould Contaminated Feeds for Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758)

Aflatoxins are toxic, carcinogenic secondary metabolites mainly produced by Aspergillus flavus fungi that is often detected in food and agricultural commodities. Calcium bentonite clay has been used historically as an anti-caking agent and a feed binder and demonstrated the ability to bind aflatoxins. Feed samples were prepared for Nile tilapia to determineaflatoxin detoxification properties of calcium bentonite clay. 0.5%, 1%, 1.5% and 2% of this clay was incorporated into Aspergillus flavus contaminated feed and labeled as TF1, TF2, TF3, TF4, and TF5 respectively. The determination and quantification of aflatoxins produced by the fungus in the feed samples were carried out by HPTLC method. The RF values of all the feed samples were confirmed to be the presence of aflatoxin B1 and AFB2, G1 and G2 toxins were not found in any of the samples. Results from this study revealed that the calcium bentonite clay at 2% effectively reduced AFB1 toxin by its adsorption properties. Moreover, calcium bentonite clay improved water stability, water absorption rate with minimal disintegration and nutrients leaching of feed samples in water.