Changes in antioxidant activity in rosa rugosa flowers at different stages of development

Abstract

Free radical scavenging activities (FRSA) of the crude aqueous extracts from Rosa rugosa fresh flowers at different developmental stages on l, l-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl free radicals, and their polyphenolic concentration, were investigated. FRSA ranged from 73.5% to 40.2% for DPPH, from 32.2% to 14.3% for hydroxyl, and from 84.6% to 78.0% for superoxide. The polyphenolic concentration varied from 19.8 to 6.9 mg catechin equivalents (CE)/g fresh weight (FW). There was a reduction in FRSA for DPPH and hydroxyl, as well as polyphenolic concentration. The decrease in polyphenolic concentration was positively correlated with declines in free radical scavenging of DPPH (r 2 = 0.961, P < 0.01) and hydroxyl free radicals (r 2 = 0.993, P < 0.01). These results demonstrated a close link between rose development, polyphenolic concentration, and antioxidant activity with stage 1 exhibiting the best polyphenolic concentration and free radical scavenging potential. © 2007 Taylor & Francis Group, LLC.