Selecting wheat varieties for tortilla production

Master of ScienceDepartment of Grain Science and IndustryRebecca MillerWheat flour tortillas are the second most consumed bread product after white pan bread. Commercial tortillas are formulated with highly viscoelastic hard wheat flours selected and grown for breadmaking. However, the inherent properties of bread flours require costly formula adjustments to enhance dough extensibility necessary for tortilla production. The objective of this study was to identify the biochemical and physical factors in wheat affecting wheat tortilla quality. Six popular hard winter wheat cultivars (1863, Armour, Clara CL, Denali, Everest, Tiger) were grown in five locations in Kansas. Wheat and flour properties were characterized using approved AACCI methods. Protein composition was determined using size-exclusion high performance liquid chromatography. Flour particle size and starch granule size were measured with laser diffraction. Tortillas were made with a laboratory hot press method. Tortilla shelf-stability over 14 days, opacity, appearance, dough machinability and specific volume were measured. Data collected from flour and tortilla tests were analyzed using ANOVA and means were compared with Tukey-Kramer HSD. In general, the flours did not differ significantly in flour or tortilla properties. Regression analysis (Pearson) showed flour protein content was highly and significantly correlated with tortilla opacity (r=-0.81), L color value (r=-0.79), a color value (r=0.80), and day 14 shelf-stability (r=0.76). Flour water absorption showed highly significant correlations with tortilla opacity (r=-0.81), L color value (r=-0.79), a color value (r=0.77) and day 14 shelf-stability (r=0.73). Tortilla opacity was highly correlated with B-type starch granules (r=-0.83). This study showed that starch granule size, flour protein content and flour water absorption appeared to influence tortilla appearance. However, repeating the study with a larger and more diverse sample set is recommended