UJI DAYA ANTIOKSIDAN EKSTRAK ETANOL UMBI DAN DAUN BEBERAPA VARIETAS KETELA RAMBAT (Ipomoea batatas (L.) L.)
Research on anti-oxidant activity of different varieties sweet potato (Ipomoea batatas (L.) L.) was carried out both qualitatively and quantitatively. Extraction was carried out by maceration using ethanol 70% as solvent. Anti-oxidant activity was tested utilizing DPPH method. Qualitatively, change in color of DPPH was observed from purple to colorless after adding certain concentration of each extracts. Quantitative analysis was carried out using spectrofotometer in the visible region at the wavelength of 521 nm. EC50 of the root extracts lies between 1453-13782 bpj while for the leaves extracts the value lies between 53-103 bpj. It was also concluded that purple sweet potato that were cultivated in different regions (Bandungan and Pacet) showed different EC50 value eventhough the difference was not significant. Statistical analysis using t-test (ɑ = 0,05) showed that there was significant difference on the anti-oxidant activity of the roots and leaves extract of sweet potatoes with the later extracts had better anti-oxidant activity.