CHEMICAL, RHEOLOGICAL AND SENSORY PROPERTIES OF WHEAT- OAT FLOUR COMPOSITE CAKES AND BISCUITS

Abstract

The effect of using Oat flour to improve the functional properties of cake and biscuit was explored. Oat flour in the cake and biscuit formulation was replaced at four levels, 25, 50, 75 and 100% with whole meal wheat flour(wmwf). Biscuit and cake containing only whole meal wheat flour was used as control. Raw materials, prepared cake and biscuits were analyzed for their proximate composition, baking quality of cake (weight, volume, specific volume) and biscuit(diameter, thickness, spread ratio, weight, volume, specific volume), color, texture, stalling and sensory evaluation. Rheological properties of mixed oat flour with whole meal wheat flour were studied. Results revealed that, the chemical composition of oat flour and whole meal wheat flour resulted in a significant increase in fibre and ash contents and a decrease in protein and carbohydrate content compared to whole meal wheat flour. Farino graph parameters showed that water absorption, dough weakening and arrival time increased as Oat Flour level increased in the blends. While dough stability and mixing tolerance index were decreased by adding Oat flour to whole meal wheat flour at all levels replacement. The adding of Oat flour to Whole meal wheat flour led to increased of transmission temperature, temperature of peak viscosity and peak viscosity. Cake weight produced from Whole meal wheat flour with oat flour were lower than compared to control, while, its volume and specific volume of cake produced from Whole meal wheat flour with oat flour was increased as the level of oat flour increased in cake. Cake produced from Whole meal wheat flour withoat flour at different levels (25, 50, 75 and 100%) caused a noticeable decrease in alkaline water retention capacity values compared with control at the same storage period. Results also showed that Hunter color parameters (L*, a*andb*) of biscuits and cakes were lightness were increased as mixing level of oat flour increased. This result was confirmed with the obtained sensorial results. Moreover, sensory evaluation of biscuits and showed that all samples were acceptable, but sample which contained oat flour had superior sensory characteristics, nutritional value and was suitable for Diabetic and Obesity.