The blue colouring the flatbread is due to the presence of anthocyanins in the corn. These are the same health promoting compounds found in purple berries and red wine.
Scientists in Mexico, home of the taco, found that tortillas made from blue corn had less starch and a lower glycemic index than their white counter parts. They also found that the blue tortillas had 20percent more protein than white.
Glycemic index (GI) is a ranking system for carbohydrates based on their effect on blood glucose levels.
Carbohydrates that break down rapidly during digestion have the highest glycemic indices. Carbohydrates that break down slowly, releasing glucose gradually into the blood stream, have a low glycemic index.
A lower glycemic index suggests slower rates of digestion and absorption of the sugars and starches in the foods and may also indicate greater extraction from the liver and periphery of the products of carbohydrate digestion.
A lower glycemic response is often thought to equate to a lower insulin demand, better long-term blood glucose control and a reduction in blood lipids.
Juscelino Tovar, an author of the study insisted that one important benefit of the lower GI blue tortillas was their potential role in preventing or controlling metabolic syndrome, a combination of disorders that increase the risk of heart disease, stroke and diabetes.
The findings of the study were published in the Journal of the Science of Food and Agriculture.