AKTIVITAS ANTIOKSIDAN EKSTRAK DAUN KACANG HIJAU, KACANG KEDELAI DAN KACANG TANAH DENGAN METODE 2,2-DIFENIL-1-PIKRILHIDRAZIL (DPPH) DAN FERRIC REDUCING ANTIOXIDANT POWER (FRAP)

• Main Author: Aristya, Tiara
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45494
• Institution: Institut Teknologi Bandung

Free radicals are a compound or molecule containing one or more unpaired electrons in its outer orbital. Antioxidant is electron donor or reductant which can reduce free radical. Natural antioxidant is commonly used are polyphenols that are found in many plants. Some research revealed that green bean, peanut, and soybean contained protein, sugar, essential fatty acids, and phenol compounds, and had antioxidant and anticancer activity. Different part of plant might contain similar compound and had similar activity. This study aims to determine antioxidant activity from leaves of green bean (Phaseolus radiatus), soybean (Glycine max), and peanut (Arachis hypogaea) by determining their IC50 of DPPH scavenging activity and EC50 of FRAP capacity, determining total phenol, total flavonoid, and total carotenoid of each extract, and analyzing their correlation with IC50 DPPH and EC50 FRAP, correlation between the IC50 DPPH and EC50 FRAP. Extraction was performed by reflux method using increasing polarity solvent, n-hexane, ethyl acetate, and ethanol respectively. Extract was monitored by thin layer chromatography (TLC) GF254. IC50 DPPH, EC50 FRAP, total phenolic, flavonoid, carotenoid content of each extract was conducted by ultraviolet-visible spectrophotometry, and analyzing their correlation with IC50 DPPH and EC50 FRAP, correlation between IC50 DPPH and EC50 FRAP using Pearson’s method. The ethanolic leaves extract of green bean had the lowest IC50 DPPH (1.9 µg/mL) and the lowest EC50 FRAP capcity (46.9 µg/mL). Ethanol leaves extract of green bean (KH3) had the highest total phenol (26.20 g GAE / 100 g), ethyl acetate leaves extract of green bean (KH2) had the highest total flavonoid (1.69 g QE / 100 g), and the highest total carotenoid (18.42 g BE/100 g) was given by n-hexane leaves extract of soybean (KK2). Total phenolic content of soybean leaves extract had high, negative and significant correlation with IC50 DPPH (0.975, p <0.01) and EC50 FRAP (0.871, p <0.01). All of ethyl acetat and ethanol leaves extract of green bean, soybean and peanut (except ethyl acetat leaves extract of peanut) were very strong antioxidant by DPPH method. Antioxidant activity of soybean and peanut leaves extracts with DPPH and FRAP methods can be estimated indirectly by determining total phenolic content. Phenolic groups were the major contributor in antioxidant activity of soybean and peanut leaves extracts using DPPH and FRAP assays. DPPH and FRAP methods gave linear result in green bean, soy bean, and peanut leaves extracts.