Abstract: The effects of reaction program and starch concentration on RVA characteristics of waxy and normal corn starches were studied,and the RVA characteristic differences between waxy corn starch and normal corn starch in different reaction programs and at starch concentrations were compared using waxy corn variety(Yunuo No. 7) and normal corn variety(Nongda 108) as material. Results showed that:(1) The RVA characteristics change under different reaction programs,whereas the differences change. Compared with normal corn starch,waxy corn starch exhibits higher peak viscosity and breakdown,and lower trough viscosity,final viscosity,setback,peak time and pasting temperature.( 2) The RVA characteristics are affected by starch concentration. With starch concentration rising,peak viscosity,trough viscosity,breakdown,final viscosity and setback gradually increase,but peak time decreases slightly. Starch cannot be pasted when the concentration is very low and the pasting temperature decreases when the concentration increases. The peak viscosity of waxy corn starch is higher than that of normal corn starch when the concentration is low,and it is reverse when the concentration is higher(11%) .

Key words: starch RVA, waxy corn, normal corn, reaction program