Flour Mixture of Rice Flour, Corn and Cassava Starch in the Production of Gluten-Free White Bread

The use of rice flour corn and cassava starch was evaluated in several formulations aiming to find a flour mixture to replace wheat flour in the production of free-gluten white bread. Production parameters were evaluated through sensory analysis. The resulting breads were evaluated taking into account physical parameters (crumb appearance, specific volume and moisture) and sensorial parameters (flavor, appearance, crumb texture, crust color and satisfaction). Regarding flavor and moisture, breads prepared with the three different ingredients were not statistically different at 5% probability by the Tuckey test. However, they differed significantly regarding the specific volume, crumb texture, crust color, degree of satisfaction and external appearance. Rice flour bread presented the best parameters, being preferred by the sensory evaluation panel, followed by corn starch bread and cassava starch bread. Breads prepared with rice flour resulted in a softer product, presenting a better consistency with small alveoli homogeneously distributed. As far as crumb texture was concerned, corn starch bread presented larger alveoli, while cassava starch resulted in bread with expandable and gummy crumb, with granulation without alveoli, and undesirable sensorial characteristics. Production parameters were established based on these results and a mixture of flours, composed by 45% rice flour, 35% corn starch and 20% cassava starch presented good results originating bread with crumb formed by uniform and well distributed cells, and pleasant flavor and appearance. Key-words: Celiac disease, gluten-free bread, corn starch, cassava starch, rice flour Author for correspondence INTRODUCTION Celiac disease is a condition in which the mucous membrane of the small intestine of glutenintolerant people is damaged by gluten, resulting in poorly absorption of nutrients and, consequently, weight loss, diarrhea, anemia, fatigue, flatulence, deficiency of folate and osteopenia (Blades, 1997; Thompson, 1997). The first description of the disease was made more than 100 years ago by Samuel Gee, as a “celiac disorder”, defined as a chronic indigestion occurring in people of all ages, particularly in oneto-five years old children (Sdepanian et al., 1999). The Brazilian Association of People with Celiac Disease (Acelbra) has approximately 600 members. However, the number of affected people is probably much higher, since, according to data from the Word Health Organization (WHO), approximately 5% of the population may present this syndrome (Doença Celiaca, 1999). The affected people should eliminate completely and during the entire life all kinds of food that contain gluten derived components originated from cereals, wheat, rye, barley and oat. The proposition of a diet for celiac people is not easy, López, A. C. B. et al Brazilian Archives of Biology and Technology 64 since the most commonly baked products, such as breads, cakes, biscuits, pizzas and pasta are usually prepared with wheat flour and are consumed on an every-day basis by most people. There are alternative products, such as cheese bread, tapioca biscuits and maize cakes in the Brazilian cuisine. The introduction of low-cost industrialized products could be a solution as in some European countries and in the USA. Brazil has a federal law (Law number 8543 of 23/12/92) that obligates food producers to indicate in the labels and packages of products containing gluten “CONTAIN GLUTEN”. A research carried out by the Consumers Defense Institute (IDEC), that examined Brazilian and imported industrialized products prepared with wheat, oat, rye, barley and their derived components, concluded that among 48 products 31 did not comply with the law. The situation could be improved if all gluten-free products had the indication “DO NOT CONTAIN GLUTEN” in their labels and packages or had the international symbol (Doença Celiaca, 1999). Brazil imports high quantities of wheat, thus attempts to replace it by products such as corn, rice and other cereals would be of great importance. Several advantages can be mentioned favoring the replacement of wheat flour by alternative flours, and these include the reduction of wheat importations and an increased consumption of flours made from cassava, corn, sorghum, and other cereals (Machado, 1996). With the objective to establish a flour mixture for use in the replacement of wheat flour, several formulations were tested taking into account the composition and the stages involved in the production of a loaf of bread adapted to the mixture. MATERIAL AND METHODS Material The ingredients used were: maize flour (Arisco), cassava starch (Marinez), rice flour (Yok), granulated white sugar (União), dried milk (Cotochés), iodized refined salt (Globo), backing powder (Fleischman), margarine (Dona Vaca), dried egg (Sohovos), xanthan gum (Keltrol FNutrasweet). All ingredients were purchased from commercial sources or directly from the suppliers, keeping the same specification in all experiments. The following equipments and utensils were used to carry out the physical analysis of the product, the technical assays for the bread preparation and the sensorial analysis: drying-sterilizing stove, FANEM, model 315 SE; electric oven LAYR, model Crystal.1.75, with a temperature control unit FORNAX 1000; dough processor Kitchen Aid; multiprocessor ARNO; balance OHAUS model MB200; loaf baking pan (500 g); bread slicer adapted to produce uniform pieces. The basic replacing formulation for the loaf of bread was determined based on several preliminary assays. The ideal proportions of the main ingredients and the development of a standard procedure was based on traditional recipes, as presented in Table 1. Table 1 Adapted formulations from gluten-free breads