Aflatoxin Detoxification Method Combining Mesoamerican Nixtamalization and Clay Absorption Techniques
Abstract
Aflatoxins are potent carcinogens produced by fungi Aspergillus flavus and Aspergillis parasiticus. Aflatoxins are able to contaminate different crops. Once ingested in the body, aflatoxins are able to cause harmful effects such as liver cancer. Mesoamerican cultures have used the nixtamalization food process on maize since the Aztec and Mayan civilization periods. The process has proven to be effective in reducing aflatoxin concentration within maize. Extensive research has shown the effectiveness of clays, particularly the montmorillonite-rich bentonite clays, to adsorb aflatoxins. This research is aimed to combine both techniques to evaluate their synergistic effects on aflatoxin detoxification. Montmorillonite samples that have previously shown high aflatoxin adsorption capacity will be used. The aflatoxin adsorption capacity of the montmorillonite samples will be evaluated using adsorption isotherms described in Kannewischer et al., (2006) with the modification of preparing aflatoxin solutions in lime saturated water (1.5 g/L Ca(OH)2) with a very basic pH, in order to simulate the nixtamalization process. The concentration of aflatoxin left in the solution will be analyzed using the High Performance Liquid Chromatography (HPLC) method. After sampling the aflatoxin solution at different pH’s varying from alkaline, to represent nixtamalization, to acidic, the experiments proved that there is reformation of aflatoxin within stomach pHs of 2 to 3. The aflatoxin changed chemical structure once exposed to alkaline pH, causing it to open its lactone ring structure and become more solubilized in water. Due to the change in chemical structure and conversion of the nonionic species to an anionic species, which was repelled by the negatively charged montmorilloinite, the adsorption of this new structure by the clay was minimal if any, while when in acidic conditions, the aflatoxin was adsorbed well by the montmorillonite. The preliminary results implied that combining the traditional Mexican nixtamalization food process and clay incorporation in processed corn products may further limit the bioavailability of aflatoxins compared to the individual methods along.
Citation
Arteaga, Stacy E (2013). Aflatoxin Detoxification Method Combining Mesoamerican Nixtamalization and Clay Absorption Techniques. Honors and Undergraduate Research. Available electronically from https : / /hdl .handle .net /1969 .1 /154908.