AKTIVITAS ANTIOKSIDAN EKSTRAK DAGING BUAH, KULIT BUAH, DAN BRAKTEA NANAS BOGOR [ANANAS COMOSUS (L.) MERR. VAR. QUEEN] DENGAN METODE DPPH DAN FRAP

• Main Author: Virna Setjiadi, Veliana
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44375
• Institution: Institut Teknologi Bandung

Free radical is a compound or an atom that has one or more unpaired electrons thus it is highly reactive. Free radicals can be found in human body and they can cause damage to the surrounding molecules and cells, resulting in degenerative diseases. Antioxidants are compunds that are able to inhibit oxidation reaction by scavenging free radicals. Naturally, human body can produce their own antioxidant. However, the increasing pollution and stress causes a rise in the amount of free radicals and the available internal antioxidant is not sufficient to scavenge all the free radicals. Therefore, a supply of external antioxidants is needed. Bogor pineapple contain phenolic and flavonoid compounds, which show antioxidant properties. The objectives of this research were to study antioxidant activites of flesh, peel, and bract of bogor pineapple using determination of IC50 DPPH (2,2-diphenyl-1-picrylhydrazil) scavenging activity and EC50 FRAP (Ferric Reducing Antioxidant Power) capacity; total phenolic and flavonoid content in various extracts of pineapple flesh, peel, and bract; correlations of total phenolic and flavonoid content in each extract with their IC50 of DPPH and EC50 of FRAP, and correlation of two antioxidant methods in sample extracts. Samples were extracted using reflux apparatus and three solvents with increasing polarity. Determination of IC50 of DPPH, EC50 of FRAP, total phenolic and flavonoid contents were done using uv-visible light spectrophotometry. Correlation of total phenolic, flavonoid content with their IC50 of DPPH, EC50 of FRAP, were analyzed using Pearson’s method. The lowest IC50 of DPPH was given by ethanol peel extract of bogor pineapple (0.13 µg/mL), while the lowest EC50 of FRAP was shown by ethyl acetate peel extract of bogor pineapple (97.34 µg/mL). Ethyl acetate bogor pineapple peel extract had the highest phenolic content (7.84 g GAE/ 100 g), while ethyl acetate bogor pineapple bract extract gave the highest total flavonoid (10.84 g QE/100 g). Phenolic content in bogor pineapple peel extract had negative and significant correlation with their EC50 FRAP. IC50 DPPH and EC50 FRAP of pineapple peel extract had positive and significant correlation. All parts extracts of bogor pineapple were categorized as strong to very strong antioxidant, by DPPH method. Phenolic compounds were the main contributor in antioxidant activities of bogor pineapple peel extracts by FRAP method. DPPH dan FRAP methods gave linear results in antioxidant activities of bogor pineapple peel extracts.