Science Snippets!

Tortillas are produced by boiling corn (Zea mais L.) in a lime solution to make masa (tortilla dough). This process is called nixtamalization. The lime and boiling process reduces levels of aflatoxin, fumonisins, and other fungi (De La Campa et al., 2004 and references therein). During nixtamalization, fumonisin B1 is hydrolyzed and the hydrolyzed fomonisin is much less toxic as fumonisin B1.

De Campa et al. (2004) studied the nixtamalization process in four small tortilla plants in Texas. They found that the production methods varied among tortilla plants. Each facility used different concentrations of lime (Ca(OH)2) and different boiling times to reduce fumonisin. In general, the authors found that fumonisin concentration was reduced with increasing lime concentrations. De Campa et al. (2004) concluded that boiling time had no apparent effect on fumonisin. All four facilities reduced the fumonisin concentration by 80% or more. The authors found that broken corn was prone to higher concentrations of fumonisin. It seems that higher concentrations of lime results in removal for the kernel's pericarp. The higher concentrations of lime also increase the pH of the water and results in the extraction and hydrolysis of fumonisin. Producing high quality tortillas is not so simple as it seems!

Reference:

De La Campa, R., J. D. Miller, and K. Hendricks. 2004. Fumonisin in tortillas produced in small-scale facilities and effect of traditional masa production methods on this mycotoxin. J. Agric. Food Chem. 52:4432-4437.