[en] Full text: Aflatoxins are secondary metabolites of toxigenic molds and are cytotoxic, carcinogenic, teratogenic and immunosuppressive materials, which cause diseases in human and animals besides the AFB1 is classified in Group 1 of the IARC as carcinogenic material [1]. Different methods of detoxification for these molecules have been reported, one which is the “nixtamalization” [2], a thermal alkaline process used to prepare the maize tortillas in Mexico [3]. Nowadays some properties of the aflatoxins are not associated with their toxicity, principally structural characteristics, due exist few information about aflatoxin characterization. In this research, the aflatoxins were characterized through UPLC, FTIR, UV-Vis, and XRD, and the structural changes in the molecules of the toxins after being subjected to nixtamalization testing two heating sources (conventional gas heating and infrared radiation) were determined. Also, the cytotoxic potential, using MMT assay, was evaluated for each treatment of aflatoxins obtained with the two evaluated heating sources. Aflatoxins showed unique behavior and degraded in different ways. The cytotoxic potential of the aflatoxins and their derivatives did not present significant differences with respect to the type of heating source (Tukey, p <0.05), but assured the effectiveness of the detoxification process. In addition, in this work, the crystalline structure of aflatoxins is reported by the first time. References: [1] IARC Working group on the Evaluation of Carcinogenic Risk to Humans 82, (2002); [2] Arámbula-Villa, et al. Journal of Food Engineering 80, 55-60 (2007) [3] Zavala-Franco, et al. Philippine Agricultural Scientist 99, 42-49 (2016). (author)