Optimization of Process Parameters and Antioxidant Activity of Extrusion Recombinant Purple Sweet Potato Rice

Using glutinous rice as the main raw material,and adding purple sweet potato powder to prepare extruded purple sweet potato rice. Three test factors were selected,including the added amount of purple sweet potato powder,extrusion temperature and moisture content of materials. Meanwhile,the anthocyanin content,texture quality and sensory score were used as comprehesive indexes to optimize single factor and response surface. The optimum processing parameters were as follows:Purple sweet potato powder 10%,extrusion temperature 80 ℃,moisture 26%. Under this condition,the extruded reconstituted purple sweet potato rice was bright purple and the highest comprehensive score was 71.08±0.79 score. The results of antioxidant activity test in vitro showed that the DPPH and ABTS scavenging rate of extruded purple sweet potato rice were 86.71% and 87.55%,respectively,showing its good antioxidant properties.