Improvement in spray-drying technology for preparation of pregelatinized cassava starch
Abstract Native cassava starch was gelatinized under different pretreatment conditions (preheating temperature, starch concentration and heating time) and spray-dried. A rotational compound central design was used to test the three independent variables: the preheating temperature, starch concentration, and heating time, and the behavior of the system was assessed by response surface methodology. The results showed a significant effect of both the preheating temperature and heating time on the cold viscosity. The combination of the preheating temperature and starch concentration affected the crystallinity, enthalpy change, solubility, and final viscosity. Modification by spray-drying resulted in a decrease in the crystalline regions, and enthalpy change, as well as an increase in the cold viscosity. The optimal conditions for obtaining partially gelatinized cassava starch with high cold viscosity and lower breakdown, desirable characteristics for commercial pregelatinized starch, are as follows: starch concentration of 25%, preheating temperature of 52 °C, and processing heating time of 10 min.