Corn tortillas account for about half the calories consumed by typical Mexican children, many of whom suffer deficiencies in iron, folic acid and zinc, according to government surveys. Corn lacks key micronutrients, resulting in developmental disorders and stunted growth.
A nonprofit fueled by Gates Foundation grants recruited Michael Dunn, the chairman of BYU's Department of Nutrition, Dietetics and Food Science, to develop a technique for adding these nutrients to corn tortilla dough, or masa, with equipment that Mexico's local millers could afford. But Dunn's first challenge was to figure out how to keep the tortillas from turning green.
"The big problem was the iron," said Dunn, who had years of private-sector experience in food-product development before coming to BYU five years ago. The Mexican government's preferred iron supplement is a substance called ferrous sulfate, which holds iron that is readily available to the human body.
"We tried it and ended up with green tortillas. We said, 'This isn't going to fly.' "
Dunn and his students experimented with other supplements, but those with the best iron absorption discolored the masa.
So they settled on a poorly absorbed supplement, electrolytic iron.
"We had to add twice as much," said Dunn, who was aided by BYU students Kathryn Burton and Adam Richins. "Half will go right through your system, but you'll absorb the other half."
BYU's tortilla project was initiated by SUSTAIN, a Washington, D.C.-based group seeking to improve nutrition in developing countries through innovative applications of food technology. Micronutrient deficiency is a major public health menace globally, particularly for nursing and pregnant mothers and small children.
"How do you add these nutrients so that it ends up in the end product and be there without adding something that isn't desirable? It sounds like an easy thing to do, but it's not," said SUSTAIN executive director Elizabeth Turner. Dunn's tortillas were shown to pack three times the niacin, thiamin and zinc, four times the iron, and five times the folic acid, all while meeting taste tests.
"It is tremendous," Turner said of the product, which has been successfully test-marketed in Mexico. "These vitamins and minerals are essential for a child's growth." The next step is to make the tortillas commercially available.
Another obstacle was finding a method for "dosing" the masa that was cost-effective. Dunn worked with a manufacturer to adapt an existing small-scale augur unit designed for wheat. These units dose the masa just before it hits the grinding stone.
"They were less than $2,000 each," Turner said.