The effect of pullulan (PUL) on the retrogradation of rice starch (RS) was investigated by means of rapid
visco-analyzer (RVA), rotational rheometer, differential scanning calorimetry (DSC), and X-ray diffraction
(XRD). RVA results showed that addition of pullulan significantly decreased the breakdown and setback
values, which meant that the short-term retrogradation of RS was inhibited. The dynamic time sweep
of samples also proved the retarding effect of pullulan on the retrogradation of RS. DSC curves showed
clearly that pullulan significantly reduced the retrogradation enthalpy of amylopectin, and the kinetics
of retrogradation was analyzed using the Avrami model. XRD results showed that recrystallinity of RS
was reduced from 11.565% to 8.841% with the addition of pullulan and this was in line with the DSC
results. It could be concluded that the addition of pullulan apparently influenced not only the short-term
retrogradation of amylose, but also the long-term retrogradation of amylopectin.