Effect of Heat-moisture Treatment on Rheological Properties of Rice Starch

In the present study,the rheological properties of rice starch before and after heat-moisture treatment(HMT)were determined. The purpose of this study was to study the steady-state rheological behavior,dynamic rheological behavior and temperature rheological behavior of rice starch subjected to heat-moisture treatment. The results showed that rice starches showed shear thinning after HMT,which suggested that HMT increased their gel strength. In the dynamic rheological measurement,it was found that the elastic modulus(G')of starch samples was greater than the viscosity modulus(G″),and the elastic modulus(G')and viscosity modulus(G″)of rice starch samples increased after HMT,while the loss tangent(tan δ)decreased. In the determination of temperature rheology,it was found that the gelatinization temperature of rice starch treated with HMT increased,also the peak temperature of elastic modulus. The results showed HMT strengthened the interactions of starch molecular chains,thereby forming an strengthened gel network structure.