Total polyphenol contents and antioxidative activity of Ipomoea batatas (sweet potato)

• Main Author: Lye, Ying Jie
• Format: Academic Exercise
• Language: English
• Published: 2008
• Subjects: TX341-641 Nutrition. Foods and food supply
• Online Access: https://eprints.ums.edu.my/id/eprint/20139/1/Total%20polyphenol%20contents%20and%20antioxidative%20activity%20.pdf; https://eprints.ums.edu.my/id/eprint/20139/

Sweet potato is one of the most important food crops in the world. All parts in sweet potato are found to be nutritive. The purpose of this study was to investigate the total polyphenol contents and antioxidative activity of the solvent extracts of sweet potato. The petroleum ether, chloroform, butanol and aqueous extracts have were obtained from three genotypes of storage roots which were purple flesh sweet potatoes from Tambunan (TSP), orange flesh sweet potatoes from Ranau (OSP), purple flesh sweet potato sweet from Ranau (RSP). The total polyphenol content of the solvent extract were assessed using the Folin-ciocalteu method which varied from 12.54 mg GAE/g to 125.4 mg GAE /g in the solvent extracts. The butanol extract had the highest total polyphenol content followed by chloroform, petroleum ether and aqueous extract. The purple flesh sweet potatoes contained more phenolic compound than orange fleshed sweet potato. The antioxidative activity of the extracts were evaluated using 2,2'- diphenylpicrylhydrazyl (DPPH) assay and compared to BHT (positive control). The butanol extract in all three genotypes of storage roots of sweet potatoes exhibited higher a antioxidative activity (ranging from 35.37% to 97.28%) when compared to BHT (ranging from 38.1 % to 90.48%) in the DPPH scavenging assay at concentration 0.02 mg! mL to 0.1 rng/mL concentration whereas the petroleum ether, chloroform , and aqueous extracts showed less potent antioxidant activities.The butanol extracts from all the which had the highest polyphenol content, were found to posses the best antioxidant activities as well. These extracts were further analysed using HPLC. And several significant peaks were detected. The results suggested that the butanol extract of sweet potato is a good source of antioxidant.