Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2005
Publication Date: 7/15/2005
Citation: Lopez-Ayala, M.P., Walker, C.E., Flores, R.A., Salazar-Garcia, M.G., Ramirez-Wong, B. 2005. Extensional viscosity evaluation of doughs used to make flour tortillas from red and white hard wheats. Meeting Abstract at the International Association of Cereal Chemists, Orlando, Florida, September 11-14, 2005. Interpretive Summary:
Technical Abstract: Characterization of wheat flour dough is essential since it provides information about the quality of the raw material and finished products such as tortillas. The objective of this research was to evaluate the extensional viscosity of doughs from flours milled at different extraction rates. Flours at 74% and 100% extraction rates from white hard winter wheat, red hard winter wheat and the Mexican wheat cultivar Rayon were studied. Wheat flours were tested for moisture, protein, ash, dry gluten, particle size distribution, and sedimentation volume. Farinograms were also obtained for the flour-water doughs. Extensional viscosity of doughs at different biaxial strain rates was measured using the lubricated squeezing flow test connected to a texturometer. Furthermore, fresh flour tortillas were made on a commercial scale, and their elasticity modulli were measured. All doughs from wheat flour milled at 100% extraction rate had higher extensional viscosity than wheat flour doughs at 74% extraction rate. Also, for all extraction rates, doughs from white hard winter wheat and red hard winter wheat flours had higher viscosities than the Mexican wheat cultivar Rayon. The extensional viscosity correlated with the sedimentation volume (r=0.738) and with particle size lower than 120 microns (r=0.680). The results of this study are important for flour millers and tortilla manufacturers.