AKTIVITAS ANTIOKSIDAN TIGA VARIETAS BUAH TOMAT (Solanum lycopersicum L. VARIETAS “AMALA”, “LARISA”, DAN “BUNCH”) DENGAN METODE 2,2-DIFENIL-1-PIKRILHIDRAZIL (DPPH) DAN FERRIC REDUCING ANTIOXIDANT POWER (FRAP)

• Main Author: Natalia Tukiman, Stephanie
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45478
• Institution: Institut Teknologi Bandung

Free radicals are atoms or molecules that have one unpaired electrons in their outer orbitals. Free radicals are highly reactive radicals form and have a very short half life. If free radicals are not inactivated, their reactivity can damage the entire cellular macromolecules, including carbohydrates, proteins, lipids, and nucleic acids. Antioxidants can scavenge free radicals by completing the lack of electrons and inhibiting the chain reaction of free radical formation. Tomato is one of plants that are known contain antioxidant activity by the community. The objectives of this research were to determine IC50 of three varieties of tomato (Solanum lycopersicum L.) using DPPH (2,2-diphenyl-1- picryhydrazyl) and EC50 of FRAP (Ferric Reducing Antioxidant Power), total phenolic, flavonoid, and carotenoid content, analyze the correlation between total phenolic, total flavonoid, and total carotenoid with IC50 of DPPH scavenging activity and EC50 of FRAP capacity, and also the correlation between the antioxidant activity of DPPH and FRAP. Extraction process was performed by reflux method using various solvents with different polarity level. Each extract was monitored by thin layer chromatography (TLC). IC50 of DPPH, EC50 of FRAP, total phenolic, flavonoid, and carotenoid content of each extract were conducted by ultraviolet-visible spectrophotometry and analyze their correlation with IC50 of DPPH scavenging activity and EC50 of FRAP capacity, and also the correlation between the antioxidant activity of DPPH and FRAP using Pearson’s method. The lowest IC50 of DPPH scavenging activity (0.14 µg/mL) was given by ethyl acetate extract of variety larisa and the lowest EC50 of FRAP capacity (28.91 µg/mL) was given by ethyl acetate extract of variety amala. The ethyl acetate extract of variety larisa had the highest total phenolic (6.27 g GAE/100 g). The n-hexane extract of variety larisa had the highest total flavonoid (5.13 g QE/100 g) and the highest total carotenoid (58.74 g BE/100 g). Total phenolic content of extract varieties amala and larisa had negative and significant correlation with their IC50 of DPPH scavenging activity and EC50 of FRAP capacity (p<0.01). All of n-hexane, ethyl acetate, and ethanol fruit extracts of amala, larisa, and bunch varieties of tomato were very strong antioxidant by DPPH method. Phenolic compounds in fruit extracts of varieties amala and larisa tomato were the major contributor in antioxidant activity. All of sample extracts gave linear result in antioxidant activities by DPPH and FRAP methods.