Pengaruh Lama Pengukusan Terhadap Daya Antioksidan dari Umbi Ketela Rambat Jingga (Ipomoea batatas (L.) L.) Bandungan

We did a study on steaming duration effect on antioxidant activity of raw and steamed (20 and 30 minutes) roots of Bandungan orange sweet potatoes (Ipomoea batatas (L.)L.). The study used DPPH (1,1-diphenyl-2-picrylhidrazyl) method. The raw roots were extracted in 2 days and the steamed roots in 3 days with maseration technique using ethanol. The qualitative test of antioxidant activity was shown by decolouration of DPPH solution. The reaction time for quantitative test using visible spectrophotometer at 521,0 nm was 5 minutes. The EC50 value for raw roots was 7133,03 ppm (713,31 mg extract), 20 minute-steamed roots was 3446,73 ppm (86,16 mg extract) and 30 minute-steamed roots was 1805,02 ppm (45,12 mg extract). Statistical analysis with ANOVA showed that there was a significant difference between raw roots, 20 minute-steamed roots and 30 minutesteamed roots. The greatest antioxidant activity was given by 30 minute-steamed roots