Reduction of aflatoxin B1 during tortilla production and identification of degradation by-products by direct-injection electrospray mass spectrometry (DIESI-MS).

OBJECTIVE To determine the effect of pH, and exposure time over the inactivation of aflatoxin B1 (AFB1) during the tortilla making process as well as the degradative molecules generated. MATERIALS AND METHODS Inactivation of AFB1 in maize-dough with alkaline pH and in alkaline methanolic solutions was determined by HPLC. Kinetics of time exposure of AFB1 in methanolic solution and the degradative products were analyzed by direct injection electrospray mass spectometry (DIESI-MS). RESULTS The alkaline pH of the maize-dough after nixtamalización between 10.2, and 30-40 minutes of resting at room temperature allows the 100% reduction of AFB1. DIESI-MS analysis of the extracts indicated the presence of two degradation molecules from AFB1. CONCLUSION The alkaline pH of maize-dough and resting time are the principal factors involved in diminishing AFB1 levels in tortillas. A procedure to the tortilla making process is proposed, which allows the reduction of remnant AFB1, avoiding the accumulative effect over consumers.