Nutritious Instant Powder Production by Extrusion Processing Using Whole Oat and Broken Rice Flour

The effects of feed moisture content of 23% and 27%; die temperature of 120°C, 145°C, and 170°C; whole oat flour (WOF); and broken rice flour (BRF) at different ratios of 25:75, 50:50, and 75:25 were studied on functional and technological properties of the extrudates. Results showed that EI, hardness, porosity, and WAI were negatively affected by increasing WOF content, while this trend had a positive effect on WSI. Higher temperature resulted in higher WAI and WSI, but EI and hardness did not change with the amount of thermal treatment. Increasing the feed moisture content had a significant effect on elevating BD, hardness, and WAI and decreasing EI, porosity, and WSI. The FTIR spectrum demonstrated that the chemical groups of the textured samples from WOF and BRF did not change after extrusion. Simultaneous increase of WOF and the die temperature could noticeably change the morphology and crystallinity of the products. The optimized grain-based instant powder in terms of functional properties such as good flowability and lower cohesiveness was determined at WOF 25:75 BRF blend, 170°C, and 27% moisture content. Our results demonstrate an innovative approach for the use of WOF in combination with BRF in the production of nutritious instant powder by extrusion.