Effect of composition on rheological properties of gluten-free dough disks for “empanadas”

M. E. GARCÍA, N.E. ZARITZKY AND A.N. CALIFANO

Rio de Janeiro, Brasil

Congreso; 2nd Mercosur Congress on Chemical Engineering,4th Mercosur Congress on Process Systems Engineering; 2005

 Dough for “empanadas”, a traditional meal in LatinAmerica, includes wheat flour that contains gluten; they are home-made or industrially prepared and sold refrigerated. When people with celiac disease eat foods containing gluten, their immune  system responds by damaging the small instestine walls. Then people affected by celiac disease cannot eat this type of meals. Gluten is the main structure-forming protein in flour, and is responsible for the elastic characteristics of the dough, thus the replacement of gluten by starch results in a major challenge to the cereal technologist mainly from the rheological point of view. The present study was designed to examine the effects of the addition of gums (G), whey protein concentrate (WPC), dry egg (E), and water (used in combination at different levels), to corn and cassava starch  on the rheological properties of “empanadas” dough. A mixture of corn and cassava starches was used in a ratio of 2:1. Xanthan (XG) and guar gums (GG) were added maintaing the experiment at 2:1(XG/GG). The formulations included corn oil and NaCl. A 24 full factorial design was chosen and the concentrations studied were: G (1.5%-3%), WPC (3.5%-6.5%), DE (3.5%-6.5%), and water (51%-55%). Percentage concentrations are given in g/100g total starch. Rheological studies involved texture analysis and viscoelastic measurements. A TAXT2i Texture Analyzer (Stable Micro Systems,UK) was used to determine the maximum force on stretching and the maximum force need to puncture a thin (2mm) dough disk. A Controlled-Stress Rheometer RS600 (Haake,Germany) was used for studying the viscoelastic properties of the formulated doughs by dynamic oscillatory experiments using a serrated plate-and-plate geometry. Storage and loss moduli, complex viscosity, and loss tangent  were determined  within the linear viscoelastic range. Formulations containing higher percentages of gums and lower water content led to an appropriate behavior for industrial production of these doughs suitable for celiac persons.