Antioxidant activities, flavonoids, ascorbic acid and phenolic contents of Malaysian vegetables

作者：Sumazian Yusuf; Syahida Ahmad; Hakiman Mansor; Maziah Mahmood^*

来源：Journal of Medicinal Plants Research, 2010, 4(10): 881-890.

• Malaysian vegetables
• antioxidant
• ascorbic acid
• flavonoid
• phenolic

Vegetable extracts of nine Malaysian vegetables; Curcuma domestica, Kaempferia galanga, Piper betel, Piper sarmentosum, Polygonum minus, Cosmos caudatus, Centella asiatica, Hydrocotyle bonariensis and Barringtonia racemosa were screened for their antioxidant properties. Total antioxidant activities of leaf or rhizome extract were assayed using different methods; ferric reducing antioxidant potential assay (FRAP), 1,1- diphenyl-2- picrylhydrazyl free radical scavenging assay (DPPH) and beta-carotene bleaching assay. Another relevant antioxidant compounds studied were total ascorbic acid content, total flavonoid content and total phenolic content. All of assays studied extracted using aqueous and boiled aqueous except for beta-carotene bleaching assay and total ascorbic acid content. DPPH free radical scavenging assay was found to be the best assay for total antioxidant while high activity of antioxidant also recorded in total phenolic content. FRAP assay showed that C. domestica contain the highest antioxidant activity in aqueous and boiled aqueous extract. Percent of inhibition using DPPH assay in aqueous extract showed that K. galanga was the highest while P. betel showed the highest in boiled aqueous extract. Total antioxidant activity using beta-carotene bleaching assay was ranged from 8.05 - 19.04% while total ascorbic acid content ranged from 0.26 - 1.82 mg/g FW. For total flavonoid content, C. domestica and P. minus showed the highest for aqueous (4.05 mg/g FW) and boiled aqueous extract (6.28 mg/g FW), respectively. Total phenolic content in C. caudatus and P. betel showed the highest content with 6.43 and 12.35 mg/g FW in aqueous and boiled aqueous extract, respectively. Most of the assays exhibited higher antioxidant activities using boiled aqueous extraction compared to aqueous extract. Only FRAP assay showed high antioxidant using aqueous extraction but DPPH assay, total flavonoid content and total phenolic content respond better in boiled aqueous extraction. These findings showed that, most of Malaysian vegetables can exhibit high antioxidant activities using boiled aqueous.

• 出版日期2010-5-18