EFFECT OF COMPOSITION ON RHEOLOGICAL PROPERTIES OF GLUTEN-FREE DOUGH DISKS FOR “EMPANADAS” M. E. García 1 , N.E. Zaritzky 1,2 and A.N. Califano 1* 1- Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA). Conicet. Fac. Ciencias Exactas, Universidad Nac. de La Plata. Argentina. 2- Depto. de Ingeniería Química, Fac. de Ingeniería, Universidad Nac. de La Plata. Argentina. Abstract. 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 2 4 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. Keywords: Gluten-free Dough, Texture, Rheology 1. Introduction. Dough for “empanadas”, a traditional meal in Latin America, 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 intestine. Specifically, finger like protrusions called villi, are lost. So, as nutrients from the food are absorbed into the bloodstream through these villi, without villi a person becomes malnourished, regardless of the quantity of food eaten. Then people affected by celiac disease cannot eat this type of meals (Arendt et al. , 2002) Gluten is the main structure-forming protein in flour, and is responsible for the elastic and extensible 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 (Gallagher et al. 2004). Gluten-free starches have been utilized to formulate breads (Ranhotra et al., 1975; Toufeili et al, 1994; Cunin, 1999, Gallagher et al., 2002, 2003; Ward and Andon, 2002; Kobylañski et al., 2004), however they fail to form a continuous phase and thus lack the necessary dough structure for the production of a good quality dough. Thus, gluten-free bakery products require polymeric substances that mimic the viscoelastic properties of gluten in doughs. * To whom all correspondence should be addressed. Address: CIDCA. 47 y 116. La Plata (1900), Argentina. E-mail: anc@quimica.unlp.edu.ar