Improving the resistance starch of rice through physical and enzymatic process

Abstract

People with obesity and diabetes mellitus in Indonesia have increased in number from year to year. One of the reasons is caused by high glycemic index (GI) value in rice as our staple food. The GI of the rice ranged from 64 ± 9 to 93 ± 11, where glucose = 100. The objective of this research is to compare several processes in decreasing the GI value of rice, i.e. acid hydrolysis; acid hydrolysis followed by autoclaving-cooling and hydrolysis by pullulanase enzyme. GI values in this study was determined through the percentage of the resistant starch (%RS) as the opposite of GI. The experiment was started by analyzing the viscosity and gelatinization temperature, moisture content, resistant starch, and carbohydrate content of the rice starch. Variations used in this experiment are the type of acid solution (hydrochloric acid, acetic acid, citric acid, and lactic acid), acid concentration (0.01, 0.05, 0.1, 0.15 and 0.2 mole / L), and period of pullulanase hydrolysis (2, 6, and 8 hours). Condition of heating cooling used was 121ºC and 4ºC. The results showed that the highest resistance starch content (7.6%) is obtained from the hydrolysis process using pullulanase enzyme for 8 hours.