Starch retrogradation studied by thermogravimetric analysis (TGA)

Thermogravimetric analysis (TGA) as an analytical method to follow retrogradation properties of rice starch was investigated in this study. Our results showed that the bound water content (Mb) of retrograded starch samples was significantly increased with the increasing of storage time. Based on the measurement of bound water, degree of starch retrogradation was determined, and it was consistent with the data obtained from differential scanning calorimetry (DSC). The degree of starch retrogradation determined from the TGA was further employed to study starch recrystallization kinetics, indicating that the recrystallization data were well suited to Avrami theory (R > 0.98). The results also found that the absorbed water content (Ma) was significantly reduced for the retrograded starch (P ≤ 0.05). These findings suggest that the TGA as well as the DSC is able to provide potential data for evaluating starch retrogradation.