Produção de macarrão pré-cozido à base de farinha mista de arroz integral e milho para celíacos utilizando o processo de extrusão

Abstract

The high production and the practice to make pastas justify their consumption by the population, especially the instantaneous. However, your consumption is limited by people who have celiac disease. The aim of this study was to produce pre cooked pastas using mix flour of brown rice and maize by extrusion cook. The surface methodology was used and the central composite design was made to study the effect of the different levels of temperature (70, 80 and 90°C), moisture (30, 35 e 40%) and maize flour (20, 30 and 40%). The response variables were water solubility index (WSI), water absorption index (WAI), initial viscosity 25°C, maximum viscosity, final viscosity, cooking time, solids losses and acidity. The raw materials and the pre cooked pastas were characterized by particle size, optical microscopy, centesimal composition, minerals, aminoacids and B1 and B2 vitamins. The textures of the best results were valued. The preference between the best results were valued and any nutritional information was given to half of the consumers. The chemical characterization indicate that the brown rice flour has nutritional advantages than the maize flour, like high value of fibers, proteins, fat, minerals and B1 vitamin. However, the increase of maize flour in the mixture was very important on the cooking quality and sensorial evaluation. The variance analysis showed that none independent variable contributed to the WAI values. Only the maize flour contributed significantly to the WSI variable. None of the independent variables contributed to the initial viscosity values, but moisture and maize flour contributed to the maximum viscosity values, although linear moisture had the highest contribution (inversely proportional). Temperature was the variable that had the highest contribution on the final viscosity. The second one was moisture followed by maize flour (inversely proportional). Among the 20 samples, T5 (70°C; 30% moisture and 40% maize flour) and T19 (80°C; 35% moisture; 13,2% maize flour) have the best behaviors during the cooking time, the resistance, less solids losses in the water cooking and good weight gain. The values of firmness showed that T5 sample was similar to commercial pastas and the T19 sample was very similar to pastas made with wheat. The sensorial evaluation indicated that, among the consumers (devoid of nutritional information), the T5 sample had the highest preference (80%). Among the consumers (with nutritional information), the T19 sample had the highest preference (70%). It was concluded that the T5 sample (40% maize flour; 30% moisture and 70°C), showed very good quality characteristics, possible to be produced for celiac people.