DOI: 10.36347/sjet.2020.v08i04.001

Pages: 59-65

This research was aimed to determine physical characteristic of purple sweet potato starch with ultrasonication method. Purple sweet potato starch was extracted using conventional method. The research used a Factorial Completely Randomized Design with three factors and each treatment was repeated three times. The factors were starch liquid ratio (1:1, 2:1), sonication time (15, 30, 45 minutes) and sonication temperature (30, 40, 50°C). The investigated parameters were bulk density, swelling power, solubility, water adsorption index, and viscosity. The result showed that solid liquid ratio of purple sweet potato starch and ultrasonication temperature had significant effect on bulk density, swelling power, solubility, water adsorption index, and viscosity. Interaction of solid liquid ratio and sonication time had significant effect on bulk density and viscosity. The interaction of the three factors had significant effect on bulk density only. Based on the lowest bulk density, the best treatment of this research was modified purple sweet potato starch with solid liquid ratio 1:1 on ultrasonication temperature 30°C at 15 minutes with swelling power 15,48%, solubility 26,17%, water absorption index 101,38%, and water content 8,29%.