Red clover extract as antioxidant active and functional food ingredient

Abstract

Red clover is a rich source of isoflavones which are reported to have beneficial estrogenic effects and, moreover, contains significant amounts of polyphenolic substances which are known for their potential bio-active antioxidant properties and radical scavenging capacity. The concentration of total polyphenols was remarkably high in the red clover extract (153 mg/g) and in a red clover based food supplement (114 mg/g), above all in comparison to soy extract (18 mg/g). In correlation with the respective total content of polyphenols, the DPPH radical scavenging capacity was found to be most pronounced in the red clover extract (EC 50: 0.32 mg/ml; ARP: 7) and the red clover preparation (EC 50: 0.50 mg/ml; ARP: 5) whereas the soy preparation showed only minor radical scavenging capacity (EC 50: 1.09 mg/ml; ARP: 2). In consideration of the beneficial nutritional-physiological and health promoting effects of isoflavones and polyphenols red clover extract could be regarded as a potent antioxidant and radical scavenging active and functional food ingredient or dietary food supplement.