Efficacy of microwave-heating during alkaline processing of fumonisin-contaminated maize

Background: fumonisins (a family of foodborne carcinogenic mycotoxins) cause health hazards to humans and animals in developing countries,and has also economic implications. therefore,the efficacy of a novel environmental friendly nixtamalization procedure to make tortillas (the main staple food for the mexican population) was investigated. methods: maize contaminated with 2136.67 ng/g total fumonisins was processed into tortillas,starting with maize grits mixed with water and calcium hydroxide that was cooked in a microwave field at 2.45 ghz during 3.75 min,and steeped 3.5 h at room temperature. the steeped maize grits (nixtamal) was stone-ground into masa (maize dough),which was then used to make tortillas. total fumonisin content was determined using monoclonal antibody columns. results: masa contained 1998.33 ng/g total fumonisins,which represents 6.5% toxin reduction. nevertheless,fumonisin concentration was reduced significantly in tortillas (up to 985.33 ng/g) due to the cooking process,corresponding to a cumulative toxin degradation of 54%. tortillas were below the maximum tolerated level,considering the european union regulatory limit for fumonisins in maize (1000 ng/g). the physicochemical and technological properties of tortillas were also considered within the acceptable margins of quality. conclusion: microwave nixtamalization was not a feasible method to reduce fumonisin content in masa to acceptable levels; however,an effective extra-reduction occurred when masa was baking into tortillas.