Effects of wheat protein fractions on flour tortilla quality

Commercial wheat protein fractions (10) were evaluated during processing for quality of tortillas prepared using pastry, tortilla, and bread flours. Protein fractions that separately modify dough resistance and extensibility were evaluated in tortillas to determine whether the proteins could increase diameter, opacity, and shelf stability. Tortillas were prepared using laboratory-scale, commercial equipment with fixed processing parameters. Dough and tortilla properties were evaluated using analytical methods, a texture analyzer, and subjective methods. Tortillas were stored in plastic bags at 22degreesC for up to 20 days. Adjustments in water absorption and level of reducing agent were made to normalize differences in functionality of 3% added proteins on dough properties. Tortilla weight, moisture, pH, opacity, and specific volume were not affected by added proteins, except for glutenin and vital wheat gluten treatments, which had decreased opacity in tortillas prepared from pastry flour. Increased insoluble polymeric protein content corresponded to decreased tortilla diameter and improved shelf stability. Treatments yielding tortillas with improved shelf stability and similar tortilla properties were produced when commercially processed vital wheat gluten products, FP600, FP6000, FP5000, or gliadin were added to pastry or tortilla flour. These wheat protein fractions improved processing and tortilla quality of wheat flours, especially pastry flour, by modifying protein content and quality.