Anti-oxidative activity in South African herbal tea, Rooibos (red bush in English, Asparathus linearis) tea extract (RTE) and grape seed extracts (Procidyn:Pro and Gravinol:Gra) was evaluated based on that in mixed tocopherol (Toc), epigallocatechin gallate (EGCG) and propyl gallate (PG). Polyphenol content in RTE, Pro, and Gra was determined to be 17, 90, and 49%, respectively in term of EGCG. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability of RTE, Pro, Gra, EGCG, PG, and Toc given as 3.29, 6.58, 2.86, 9.98, 4.26, and 1.00 per unit polyphenol content, respectively. Anti-oxidative ability in RTE, Pro, Gra, EGCG, PG, and Toc was determined by adding different amounts as 500ppm polyphenol to be present in the substrate of methyl linoleate in the non-aqueous and O/W emulsifying systems. Anti-oxidative activity was found to follow the order, Control Toc RTE Pro Gra EGCG PG in the non-aqueous system and EGCG Control Gra Pro Toc PG RTE in the emulsifying system. Intensity of synergistic effects of ascorbic acid (AA), citric acid (CA) and phosphatidylethanolamine (PE) for RTE followed the order, Control RTE RTE AA RTE CA RTE PE in the two systms. Main component present in RTE was indicated by TLC and IR to be rutin.
