46E-11 |
Evaluation of the radical scavenging properties of red clover as functional food supplement |
G. T. KROYER, Institute of Food Chemistry and Technology, University of Technology Vienna, Getreidemarkt 9, A-1060 Vienna, Austria There is an increasing interest in the beneficial health effects of plant derived phytoestrogens. Red clover is a rich source of isoflavones which are reported to have estrogenic activity. With regard to the comprehensive nutritional-physiological and health promoting effects the potential bio-active antioxidant properties and radical scavenging capacity which is primarily based on the content of total polyphenols might be of great evidence. The objective of this study was to determine the content of isoflavones and of total polyphenols in red clover extract and a standardized red clover preparation, and to evaluate their respective free radical scavenging capacity. HPLC analysis was carried out for the determination of the individual isoflavones genistein, daidzein, biochanin A and formononetin. Total polyphenols were analyzed according to the Folin-Ciocalteu method. The radical scavenging capacity was evaluated by the DPPH radical scavenging method in terms of their Anti-Radical Power ARP. Red clover extract contain significant amounts of isoflavones (total content: 111 mg/g). The content of total polyphenols was remarkably high in the red clover extract (153 mg/g) and in the red clover preparation (114 mg/g), above all in comparison to a standardized soy preparation (18 mg/g). Accordingly, the Anti-Radical Power was found to be most pronounced in the red clover extract (ARP: 7) and the red clover preparation (ARP: 5) whereas the soy preparation showed only minor radical scavenging capacity (ARP: 2), correlating with the respective total content of polyphenols. According to the results of this study and in consideration of the beneficial nutritional-physiological and health promoting effects of isoflavones and polyphenols, red clover preparations could be regarded as an effective and functional dietary food supplement due to their significant content of bio-active substances and significant radical scavenging capacity.
Handout (.doc format, 21.5 kb)
Session 46E, International
|