Thermal and pasting properties of native and acid-treated starches derivatized by 1-octenyl succinic anhydride

The thermal and pasting properties of native and acid-treated starches derivatized by 1-octenyl succinic anhydride (OSA) were investigated. The pasting properties were tested using a Rapid Visco-Analyzer. The gelatinization and retrogradation properties were determined using a differential scanning calorimeter. OSA starches prepared from both native tapioca and rice starches had significantly higher peak viscosity, final viscosity, and setback than their native starches. Also, even when DP of tapioca starch was reduced by half, the peak viscosity of this OSA starch was still higher than that of native tapioca starch. The enhancement in peak viscosity was related to the high swelling volume of OSA starch, hydrophobic interactions and amylose–OSA inclusion complex. The gelatinization temperature of OSA starches decreased, whereas the gelatinization temperature range increased. The gelatinization enthalpy of OSA-modified rice-based starches was reduced, however, that of OSA-modified tapioca-based starches were not significantly different (P > 0.05). After storing gelatinized starches at 4 °C for 2 weeks, the enthalpy values for melting the retrograded OSA starches were less than the native starches. This effect was very apparent in tapioca-based starch. OSA starches had lower gelatinization temperature and slower retrogradation, but significantly higher peak viscosity than their native starches.