Note:: Antioxidant and antibacterial activities of Rosa damascena flower extracts

Rosa damascena Mill. is one of the most important Rosa species for the flavour and fragrance industries. The high amount of residues of spent flowers after steam distillation and the potential use of their essential oils as natural antioxidants and antimicrobials lead to determine the antioxidant and antibacterial activities of fresh and spent Rosa damascena flower extracts. The total phenolic contents were 276.02+/-2.93 mg gallic acid equivalent (GAE)/g in FF (fresh flower) extract and 248.97+/-2.96 mg GAE/g in SF (spent flower) extract. FF and SF extracts showed 74.51+/-1.65 and 75.94+/-1.72% antiradical activities at 100 ppm. The antioxidant activity of FIF extract (372.26+/-0.96 mg/g) was higher than that of SF extract (351.36+/-0.84 mg/g). Antibacterial activity of the extracts was determined by the agar diffusion method against 15 species of bacteria: Aeromonas hydrophila, Bacillus cereus, Enterobacter aerogenes, Enterococcus feacalis, Escherichia coli, Escherichia coli O157:H7, Klebsiella pneumoniae, Mycobacterium smegmatis, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus and Yersinia enterocolitica. Statistical differences among bacteria were significant at p<0.05. Both extracts were effective against all the bacteria except E. coli O157:H7, although the FF extract was more effective than the SF extract. FF and SF extracts showed the strongest effects against S. enteritidis and M. smegmatis, respectively.