Physical properties of octenyl succinic anhydride modified rice, wheat, and potato starches

The physical properties of octenyl succinic anhydride (OSA) starches prepared from rice, wheat, and potato starches were studied. Rice and wheat OSA starches had significantly higher peak viscosity (PV), hot paste viscosity (HPV), and cool paste viscosity (CPV), but potato OSA starch had only significantly higher CPV, relative to the native starch. The gel hardness was higher with lower degree of substitution (DS) but lower with higher DS OSA compared to native starch. The swelling volumes (SV) of rice and wheat OSA starches were significantly higher compared to native starch, but the SV of potato OSA starch was slightly lower at high DS. The gelatinization temperature (GT) of rice OSA starches was sharply lower at low DS; for wheat OSA starch it was slightly lower even at high DS, but potato OSA starches had higher GT than the native starch. The enthalpy of all the OSA starches decreased gradually with increased DS. This study showed that the magnitude of changes in physical properties of OSA-modified starches depends not only on their DS but also on the botanical origin of the native starches.