Optimization for parameters of indica rice resistant starch of type RS_3 prepared by ultrasonicauxiliary and dualenzyme method

The indicaresistant starch of type RS_3 was prepared using indica starchpregelatinized by microwave as a material by means of the ultrasonic intermittent auxiliary and step debranchingenzymatic hydrolysis of isoamylase and pullulanase.Based on the single factor experiments,the yield of indica rice resistant starch of type RS_3 was the response value,a response surface methodology was used to optimize the parameters of indica rice resistant starch of type RS_3.The results showed that under the conditions: starch mass fraction,10%; isoamylasehydrolysis temperature,50 ℃; isamylase hydrolysis p H,5.0; pullulanase hydrolysis temperature,60 ℃; pullulanase hydrolysis p H,4.5; ultrasonic power,70 W,the optimal parameters were obtained as follows: isoamylase amount,16 U / g;isoamylasehydrolysis time,3 h; pullulanase amount,8 U / g; pullulanasehydrolysis time,2.2 h; ultrasonic treatment time,7 min; ultrasonic intermittent time,2.7 h.Under these conditions,the yield of indica rice resistant starch of type RS_3 was 18.19%.