AKTIVITAS ANTIOKSIDAN EKSTRAK BATANG, KULIT BUAH, DAN DAGING BUAH NAGA SUPER RED [HYLOCEREUS COSTARICENSIS (F.A.C. WEBBER) BRITTON & ROSE] DENGAN METODE DPPH DAN ABTS

• Main Author: Ilham, Nadia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44366
• Institution: Institut Teknologi Bandung

Free radicals are atoms or group of atoms that have groups of unpaired electrons. Free radical can cause damage to other molecule because the molecule attracts electrons around it to achieve stability. Its reactivity can damage all types of cellular macromolecules, including carbohydrates, proteins, lipids and nucleic acids. These reactive compounds cause degenerative diseases including cancer. Antioxidants are compounds that can inhibit the oxidation reaction to scavenge free radicals. Most of the plants may have antioxidant activity when it contains compounds that can scavenge free radicals, such as flavonoids and phenolic compounds. Super red dragon fruit of stem, peel and flesh extracts known to contain antioxidant compounds. The objectives of this research were to study antioxidant activities of various different polarity extracts (n-hexane, ethyl acetate and ethanol) from stem, peel and flesh of super red dragon fruit (Hylocereus costaricensis) using DPPH and ABTS assays; total phenolic and flavonoid content in various extracts of super red dragon fruit of stem, peel and flesh; correlations of total phenolic and flavonoid content in each extract with their IC50 of DPPH and ABTS, and correlation of two antioxidant methods in sample extracts. Samples were extracted by reflux apparatus using increasing polarity of solvents. Determination of IC50 of DPPH, IC50 of ABTS, total phenolic, and flavonoid content were performed by UV-visible spectrophotometry and its correlation with IC50 of DPPH and IC50 ?» !???????? ®?ð?ð?ð±??±?± ? ???±¸ ­?????± ??????????±?í?¸?????????í?? ®±? ?± »?±?í ±??? ®? of super red dragon fruit gave the highest antioxidant activity by DPPH method (2.688 µg/mL) and ethanol peel extract of super red dragon fruit showed the highest antioxidant activity by ABTS (1.548 µg/mL). Ethyl acetate super red dragon fruit husk extract had the highest phenolic content (4.557 g GAE/100 g) and flavonoid content (12.629 g QE/100 g) Total phenolic content in flesh extract of super red dragon fruit had negative and significant correlation with their IC50 of ABTS, while total flavonoid content in stem extract of super red dragon fruit had negative and significant correlation with their IC50 of ABTS. All parts extracts of super red dragon fruit (except n-hexane flesh extract) of super red dragon fruit can be categorized as very strong antioxidant by DPPH method. Flavonoid compounds were the major contributor in antioxidant activities of super red dragon fruit stem extracts, meanwhile phenolic compounds were the major contributor in antioxidant activities of super red of dragon fruit flesh extract by ABTS method. DPPH and ABTS methods showed linear results in antioxidant activities of super red dragon fruit flesh extract.