In the study, antibacterial activities of the seed extracts of three different grapes were examined against fifteen bacteria, and total phenolic contents of the extracts were additionally determined. The contents of total phenolic compounds of the grape seed extracts were 589.09 (Hasandede), 506.60 (Emir) and 549.54 (Kalecik Karasi) mg gallic acid equivalent (GAE) per gram with acetone:water:acetic acid (90:9.5:0.5). These extracts at 1%, 2.5%, 5% and 10% concentrations were tested for their antibacterial effects by using the agar diffusion method against some pathogenic and spoilage bacteria including Aeromonas hydrophila, Bacillus cereus, Enterobacter aerogenes, Enterococcus faecalis, Escherichia coli, E. coli O157:H7, Klebsiella pneumoniae, Mycobacterium smegmatis, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus and Yersinia enterocolitica. All tested bacteria were inhibited by the grape seed extracts using agar well diffusion method. The most sensitive of the bacteria was A. hydrophila while Hasandede grape seed extract was the most inhibitive extract on test bacteria. Hasandede seed extract at 10% concentration gave the largest inhibition zone diameter (30.67 mm) against A. hydrophila. According to serial dilution method, while all the grape seed extracts at 0.5% and 1% concentrations had generally bacteriostatic activities against E. coli O157:H7, the same extracts appeared to have bactericidal effects at concentrations above 2.5%. In addition, the extracts at all concentrations had bactericidal activities against S. aureus at the end of 48 h. and A. hydrophila at the end of 1 h.

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±2.93mg gallic acid equivalent (GAE)/g in FF (fresh flower) extract and 248.97±2.96mg GAE/g in SF (spent flower) extract. FF and SF extracts showed 74.51±1.65 and 75.94±1.72% antiradical activities at 100ppm. The antioxidant activity of FF extract (372.26±0.96mg/g) was higher than that of SF extract (351.36± 0.84mg/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.

All yields, chemical compositions, free radical scavenging activities and reducing/antioxidant capacities of extracts and essential oils of Turkish oregano changed importantly depending on vegetative periods of growing season.

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Eighteen extracts of spices commonly consumed worldwide and grown naturally in Turkey were tested against twenty three bacterial strains to compare their antibacterial effects with eleven antibiotics. Eight pathogens and fifteen lactobacilli isolated from chick intestine were used as the test microorganisms. Pathogens (six different Staphylococcus aureus strains, Escherichia coli ATCC 25922 and Yersinia enterocolitica ATCC 1501) were grown in Nutrient broth and lactobacilli in MRS broth. Hop extracts formed inhibition zones against S. aureus strains of up to 36 mm. Inhibitory effects of hop extracts against S. aureus were generally higher than that of erythromycin as antibiotic. Helichrysum compactum extract produced an inhibition zone of 23 mm to E. coli ATCC 25922 and 26 mm to Y. enterocolitica ATCC 1501. Helichrysum compactum extract inhibited the growth of Y. enterocolitica ATCC 1501 more than other spice extracts. While inhibition zones of these extracts against lactobacilli were found smaller than on S. aureus strains, inhibition zones of the same extracts against lactobacilli were found similar to those of E. coli ATCC 25922 and Y. enterocolitica ATCC 1501.

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