Potential of Tartaric Acid in Combination with Infrared-Microwave Heating as a Method for Aflatoxin Reduction in Maize

To evaluate the effect of acidification in combination with a non-ionizing radiation treatment on the stability of B-aflatoxins (AFB₁ and AFB₂), samples of maize flour (particle size of <420 μm) contaminated with B-aflatoxins (140 ng/g) were chemically treated with tartaric acid at three different levels, and subsequently, thermally-treated in an infrared-microwave coupled system. The flour moisture content (MC) was adjusted at 35 and 40% by means of aqueous tartaric acid at 0, 2 and 4% (w/w). The effects of the two variables (MC and organic acid addition) were analyzed as a completely randomized factorial 2×3 design. The combination of non-ionizing radiation with MC and tartaric acid, significantly affected (P<0.01) the extent of aflatoxins reduction in the processed maize. The recovered aflatoxins decreased with an increase in MC and tartaric acid content (P<0.01). The maximum percentage of aflatoxins degraded in the physicochemically treated milled maize ranged from 43 to 87%. Even when using a short time during the thermal treatment (3 min), acceptable pH and MC in the processed flours were obtained. According to these results, physicochemical inactivation appears to be a promising method for aflatoxin degradation in maize.