Shelf life extension of corn tortillas

Abstract

The tortilla segment of the Mexican food market in the United States is rapidly growing. Tortillas are being used in many different mainstream applications, including wraps, lasagna, pizza, and appetizers. In 2000, the tortilla market was a $4 billion industry and with more than 85 billion tortillas consumed in the United States alone. As Mexican food becomes more common in the American diet, consumers start to branch out into a more authentic presentation of Mexican food. This causes a shift in consumption from flour to corn tortillas. As the consumer demand for corn tortillas increases, food manufacturing companies are challenged with producing a tortilla that will retain its softness, pliability, foldability, and flavor while remaining safe for consumption over several months. Since tortillas have two modes of deterioration, mold and staling, there are several factors that need to be considered. Hurdle technology is employed to prevent mold growth. By adjusting water activity, pH, storage temperature, and addition of preservatives mold growth can be prevented for a period of several months. Retaining tortilla texture over time is much more complicated. Tortillas stale through a complicated process of starch retrogradation. During cooking, the starch granules gelatinize and amylose and amylopectin leech out of the granules. After the tortillas are baked, the starch immediately begins to retrograde. The amylose and amylopectin complex together form a matrix that stiffens the tortilla. Based on current research, the shelf life of a corn tortilla can be extended through a combination of CMC (0.5%), maltogenic amylase (1650 Activity Units), sorbitol (3%), glycerol (4%).