Chapter 13 - Industrial Production of Maize Tortillas and Snacks

Abstract

Maize kernels, water, and lime are the three basic ingredients utilized in alkaline cooking for production of nixtamal, which is ground into a masa suitable for table tortillas, corn chips, or tortilla chips. Furthermore, other additives such as hydrocolloids, emulsifiers, acidulants, and preservatives are commonly added to table tortillas to enhance shelf life. For production of snacks, oil, salt, and flavorings are additional ingredients, which affect flavor, mouthfeel, and sensory attributes. Table tortillas are obtained by three major processes: traditional, industrial fresh masa, and from dry masa flour. The traditional and industrial processes consist of cooking maize kernels in the presence of a lime solution for about 30–40min followed by overnight steeping for 8–16h. The lime-cooked maize (nixtamal) is washed to remove excess lime and then stone-ground to transform it into masa. The resulting masa is formed into tortilla discs, which are baked in continuous three-tier gas-fired ovens. Industrial production of dry masa flours is accomplished by lime-cooking, washing, nixtamal grinding, drying, sieving, regrinding coarse particles, resieving, classifying, and blending to meet certain requirements. The dry masa flour is fabricated with carefully controlled particle size distribution, water absorption, and pH. Dry masa flour is reconstituted into masa by blending with water for a few minutes. The resulting masa is further sheeted, cut, and baked into table tortillas, directly fried into corn chips, or baked and fried into tortilla chips. The two major alkali-cooked snacks are extruded corn chips and tortilla chips. These are commonly produced from coarsely ground masa. For corn chips, the masa is extruded, cut into different forms, and fried directly. For tortilla chips, masa pieces are baked before frying to reduce the moisture content so that they absorb less oil and have a firmer texture and stronger flavor. Regular tortilla chips are less energy dense compared with corn chips because they absorb about 12% less oil during frying. The snack industry also manufactures light tortilla chips and fat-free or baked tortilla chips.