LAUSR

Red beet tubers (Beta vulgaris L.) contain 5-O-beta-glycoside betacyanin compounds which have many benefits. One of which is an antioxidant. Activity study, have been done antioxidant acting test from red beet tubers (Beta vulgaris L.) was extracted using the Ultrasonic Assisted Extraction (UAE) method using a water solvent and dried by freeze-drying method for 48 hours. Betacyanin was identified by thin-layer chromatography with Rf value 0.7166 and a wavelength of 535 nm analyzed by UV-Vis spectrophotometry. The FTIR spectrum shows that isolates contain functional groups that ware similar to betacyanin standard (Sigma Aldrich). Betasianin obtained in red beetroot extract with levels of 98.6474%. The red beetroot is stable at 40 °C and pH 5. Test its antioxidant activity using the DPPH method (1,1-diphenyl-2-picrylylhydrazyl) with a wavelength of 515.50 nm. The results of this study indicate the antioxidant activity from of red beet tubers (Beta vulgaris L.) with IC50 values of 21.8878 µg/mL, compared to IC50 values of vitamin C 7.1099 µg/mL. it can be concluded that the red beet tubers have a potent antioxidant activity (high antioxidant <50 µg / mL).