PREPARATION AND EVALUATION OF PHYSICAL AND CHEMICAL PROPERTIES OF GLUTEN-FREE BISCUITS

Abstract

This study was carried out to use whole meal quinoa flour, papaya powder, gelatinized corn flour, rice flour, defatted soya flour and potato starch for production of gluten-free biscuits suitable for celiac patients. Carboxy methyl cellulose (CMC) was used to improve the quality of gluten-free biscuits at level of 0.1%. Biscuit made of 100% wheat flour (WF) 72% extraction was prepared for comparison. Chemical composition, mineral contents of basic raw materials and rheological properties of used mixtures were determined, also, the chemical composition, mineral content and physical properties (color values, baking quality and sensory attributes) for final products were evaluated. The results showed that, papaya powder contained the highest value of crude fiber, calcium and iron content, and this increase was reflected in the increasing of the same aforementioned components in the final product with the increasing level of papaya powder. Also, quinoa flour contained the higher value of protein, ash, fiber, zinc, iron and calcium compared to wheat flour. And through the evaluating the quality of the final product the results indicated that no evident discrepancy was observed for instrumental weight, volume, diameters and thickness between the control biscuit and the gluten free biscuit samples according to statistical analysis. On other hand, the results indicated that, in terms of the color of final product was tends to darkness with the increasing ratio of papaya powder (decrease L* value), on contrary of redness (a*) values which increased in the produced gluten free biscuit samples. Sensory evaluation of gluten free biscuits indicated that all samples were acceptable, but sample which contained whole meal quinoa flour, papaya powder, gelatinized corn flour, rice flour, defatted soya flour and potato starch at ratio 20:20:15:15:15:15 respectively had superior sensory characteristics compared to other gluten free samples and highly nutritional value compared to control (100% wheat flour) and suitable forceliac patients.