Textural properties of defatted soy-rice based extrudates

Extrusion cooking is a popular means of preparing snack foods and ready-to-eat breakfast cereals using starch-based raw materials. Snacks contribute an important part of many consumers in daily nutrient and calories intake. A ready to eat extruded food was developed using brabender single screw laboratory extruder by incorporation of defatted soy flour with rice flour. The effect of moisture content (12 to 24 per cent (w.b.), defatted soy flour in the blend ratio (10 to 26 per cent) and die head temperature (160 to 2000C) were studied on the textural quality such as crispness, hardness and cutting strength of the extruded snacks. It was observed that at the lower value of moisture content (15 per cent) of feed and defatted soy flour to rice flour blend ratio (14:86) the crispness of snacks was highest. The crispness decreased up to 1850C die head temperature beyond 1850C temperature the crispness increased. Similarly the crispness of the product gradually decreased by increasing or decreasing defatted soy flour to rice flour ratio blending ratio beyond 14:86. The lowest hardness was obtained nearly at 14:86 defatted soy flour to rice flour blend ratio and 15 per cent moisture content of feed as the value of moisture content of feed increased the value of hardness also increased. The minimum cutting strength was observed at 1700C die head temperature. Further it was observed that the maximum value of crispness lies nearly higher side of die head temperature and lowest hardness and cutting strength was obtained at lowest value of moisture content i.e. 15 per cent and 14:86 blend ratio.