AKTIVITAS ANTIOKSIDAN EKSTRAK DAUN, RANTING, DAN KULIT BUAH MANGGIS (GARCINIA MANGOSTANA L.)

• Main Author: Khairunnisa Ramadhita, Nisrina
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/66120
• Institution: Institut Teknologi Bandung

Free radicals are unstable molecules with one or more unpaired electrons in their outer orbital. In order for them to be stable, free radicals will take electrons from other molecules. Antioxidant is a compound that can reduce the negative effects of free radicals. One source of natural antioxidant is mangosteen. The objectives of this research were to examine the antioxidant activity of the leaves, branches, and peels of the mangosteen (Garcinia mangostana L.) using the DPPH and CUPRAC methods, total phenolic content (TPC) and total flavonoid content (TFC), analyze the correlation between TPC and TFC to the antioxidant activity, the correlation between two methods in sample extracts, and found the levels of some flavonoid compounds in extract. Extraction was performed by reflux method using solvents: n-hexane, ethyl acetate, and ethanol. Determination of antioxidant activity with DPPH and CUPRAC, TPC and TFC were performed by UV-visible spectrophotometry. The correlation between TPC, TFC and antioxidant activity as well as the correlation of the two testing methods were conducted by Pearson’s method. Antioxidant activity of mangosteen leaves, branches, and peels extracts had antioxidant activity by DPPH in the range of 39.920 – 489.708 mg AAE/g and antioxidant activity by CUPRAC in the range of 116.360 – 570.400 mg AAE/g. The highest TPC was given by the ethanolic extract of the leaves (49.525 ± 4.263 g GAE/100 g) and the highest TFC was given by the n-hexane extract of the fruit peels (13.859 ± 1.451 g QE/100 g). Total phenol and flavonoid levels had significant and positive correlation with antioxidant activity, except for the n-hexane leaves extract using the DPPH method. Antioxidant activity by DPPH and CUPRAC methods gave positif and significant correlation. In general phenolic and flavonoid compounds in mangosteen extract had great contribution to antioxidant activity by DPPH and CUPRAC methods. The DPPH and CUPRAC methods showed linear results in antioxidant activity of mangosteen extracts. The ethanol peel extract of mangosteen contained rutin 0.0327% and kaempferol 0.0049%