Effect of ultrasonic assisted extraction on Dayak onion powder extraction (Eleutherine palmifolia)

Dayak onion (Eleutherine palmifolia) is a typical plant of Central Borneo, Indonesia, which contains flavonoids, saponins, polyphenols, alkaloids, glycosides, steroids, phenolic, tannins, triterpenoids, and quinones. It has bioactivity as an antioxidant. Extraction using the ultrasonic assisted extraction (UAE) method can increase phenol compounds and antioxidants in a shorter time. The purpose of this study was to determine the effect of variations in the amplitude and timing of sonication of purified water-based UAE to increase the value of antioxidant activity and the total value of phenol from Dayak onion powder extract. The amplitude variations used in this study were 20%, 35%, and 50%, and the variations of the sonication time used were 5, 10, and 15 minutes. Antioxidant activity was tested using the DPPH (1,1-dyphenyl-2-picrylhydrazyl) method. Total phenol content was tested by the Folin-Ciocalteu method. In the results of this study, the best value for antioxidant activity on Dayak onion powder extract was at a variation of 50% amplitude and 5-minute sonication time, which was 2.433 ± 0.283 mg/ml. While the best value on the test of total phenol of Dayak onion powder extract was at a variation of 35% amplitude and 5-minute sonication time, which was equal to 6.558 ± 1.68 mg GAE/g. Based on the results of ANOVA statistical analysis, it was found that there was a significant effect on increasing antioxidant activity with a significant value of 0.048 on variations in the combination of amplitude and sonication time.