Effect of Microwave Heating during Alkaline‐Cooking of Aflatoxin Contaminated Maize

Abstract: To evaluate the effectiveness of maize detoxification achieved with a modified tortilla‐making process (MTMP), maize contaminated with aflatoxin B 1 (AFB 1 ) and aflatoxin B 2 (AFB 2 ) at levels of 22.46, 69.62, and 141.48 ng/g (AFB 1 + AFB 2 ) was processed into tortillas. Aflatoxin content was determined according to the 991.31 AOAC official method. Based on the results obtained with spiked samples (0.78 to 25 ng/g), the mean recovery was 92%, with a standard error of 1.2, and a coefficient variation value of 4.4%. The MTMP caused 68, 80, and an 84% decrease in aflatoxin content, respectively. Extract acidification (as occurs during digestion) prior to mycotoxin quantification caused some reformation of the aflatoxin structure in tortillas (up to 3%). According to these results, the MTMP seems to be safe for decontamination since a low percentage of the initial aflatoxin concentration can be reverted to the original fluorescent form upon acidification. Practical Application: The potential presence of aflatoxins in maize destined for human consumption is a serious problem to the Mexican food supply, as these toxic compounds may persist during the traditional alkaline‐process for tortilla elaboration. Consequently, new detoxification procedures are needed that eliminate or at least minimize the aflatoxin risk, through lowering aflatoxin concentration in maize‐based products. Under these considerations, the use of MTMP is recommended, since it has definite advantages including non‐production of wastewater and reduced energy/time consumption.