Optimization of pre-gelatinization conditions of unripe local banana starch using response surface methodology

Green or unripe banana is the newly potential low cost sources for starch, but its native state demonstrated some limitations in the application in food industries. These limitations can be overcome by modification and one of the modification methods that is non- laborious and inexpensive is the pre-gelatinization method. The aim of this research was to discover the optimum conditions for the pre-gelatinization method. Starch extracted from the unripe banana (maturity stage 2) was modified and optimized using response surface methodology (RSM). A central composite design (CCD) approach was conducted to analyse the temperature (°C) and time (mins) effects on the swelling power (SP) and solubility index (SI) of the starch. SP ranged from 1.96 to 2.23 g/g and SI ranged between 3.96 and 8.22%. The maximum SP and SI were obtained at the following optimum condition: 50.13°C and 14.40 mins. The response values obtained at the predicted optimum conditions were then verified and it was observed that there is no significant difference (p-value > 0.05) between the predicted and experimental values. The R 2 value was 99.98% and the lack-of-fit values also demonstrated no significant difference. Thus, it indicated that the optimum condition predicted by RSM could be accepted and feasible to be carried out. Overall, the outcomes of this work can be a useful reference to assist the food industries in developing and producing improved properties of local modified starch.