AKTIVITAS ANTIOKSIDAN EKSTRAK DAUN, BATANG, DAN UMBI UBI JALAR UNGU (IPOMOEA BATATAS L.)

• Main Author: Amalia, Riza
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/66053
• Institution: Institut Teknologi Bandung

Antioxidants are substances that can deactivate free radicals. The one source of natural antioxidants is sweet potato. The objectives of this research were to investigate the antioxidant activity of leaves, stem, and tubers extracts of sweet potato through the determination of antioxidant activity based on equivalence with ascorbic acid, to determine phenolic and flavonoids content, to analyze the correlation between TPC and TFC on antioxidant activity, to analyze the correlation between the DPPH and CUPRAC methods, to determine the levels of several flavonoid compounds. Extraction was conducted by reflux method using n-hexane, ethyl acetate, and ethanol. Determination of antioxidant activity by DPPH and CUPRAC method, TPC and TFC by UVvisible spectrophotometry, statistical analysis of significant level tests using ANOVA - post hoc Tukey. Correlation of TPC and TFC on the antioxidant activity and correlation of 2 methods by Pearson's method. Antioxidant activity of sweet potato extracts using DPPH method showed values in the range of 6.572-290.894 mg AAE/g sample, and CUPRAC method in the range of 25.169- 621.254 mg AAE/g sample. The highest TPC was found in the ethanol leaves extract (20.885 g GAE/100 g), while the highest TFC was found in the ethyl acetate leaves extract (10.048 g QE/100 g). In general, TPC and TFC had a significantly positive correlation with an antioxidant activity using DPPH and CUPRAC methods, and both methods showed a positive and significant correlation. In general, phenolic and flavonoid compounds greatly contributed to antioxidant activity by DPPH and CUPRAC methods, and both methods showed linear results. Ethanol extract of sweet potato stem contained luteolin 7-O-glucoside, rutin, quercetin, kaempferol, and apigenin, with levels of 0.115% - 0.399%.