Staphylococcus aureus is one of the major causes of food-borne
pathogenesis. Antibiotic consumption for these pathogens has been
increasing year by year world-wide. In order to decrease the use of synthetic
antibiotics, fresh fruits and dry herbs consumed as beverages in regular diets
were examined as potential natural antibiotics for the treatment of food based
infections against Staphylococcus aureus.
Herbs consumed as tea infusions including Pimpinella anisum L. (anise),
Anthemis arvensis L. (camomile), Rosa canina L. (rosehip), Salvia fruticosa
Mill (sage) and fresh fruit juices including Vitis vinifera L. (grape), Citrus
sinensis L. (orange), Prunus persica L. (peach) and Punica granatum L.
(pomegranate) were selected as samples of hot or cold consumed
beverages in our daily diets. Extracts of fresh fruit juices were prepared in
methanol, on the other hand, tea infusions of herbs were filtered and
lyophilized. Antioxidant capacities of the plant samples were investigated by
radical scavenging methods, namely 2&rsquo / 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) as well as
determination of total phenolic and flavonoid contents. Furthermore,
antimicrobial activities of plant samples were determined by minimum
inhibitory concentration and minimum bactericidal concentration methods
along with disc diffusion method.
Trolox equivalent antioxidant capacities (TEAC) of the herbal tea infusions
obtained by ABTS radical scavenging method were ranged between 48.38 ± / 1.242 and 715.73 ± / 4.265 (&mu / mol Trolox equivalent (TE)/g of extract) while,
TEAC values of fresh fruits juices were between 26.86 ± / 0.217 and 73.55 ± / 0.973 (&mu / mol Trolox equivalent (TE)/g of extract). Moreover, EC50 values of
the tea infusions obtained by DPPH radical scavenging method were ranged
between 0.05 ± / 0.001 and 1.53 ± / 0.004 (mg/mL) while, EC50 values of the
fruit juices were 1.6 ± / 0.014 and 2 ± / 0.093 (mg/mL). Total phenolic content of
the plant samples tested in this study were varied from 1.383 (&mu / g gallic acid
equivalent (GAE)/mg of extract) to 159.167 (&mu / g gallic acid equivalent
(GAE)/mg of extract) and total flavonoid content varied from 0.111 (&mu / g
quercetin equivalent (QE)/mg of extract) to 201.15 (&mu / g quercetin equivalent
(QE)/mg of extract).
Sage, orange and grape displayed higher antimicrobial activities with values
of 1.5, 6 and 6 mg/mL minimum inhibitory concentrations and 1.5, 24 and 24
mg/mL minimum bactericidal concentrations, respectively. Inhibition zone
diameters of sage, orange and grape were found to be 9, 9 and 11 mm.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12612999/index.pdf |
| Date | 01 March 2011 |
| Creators | Barut, Burak |
| Contributors | Coruh, Nursen |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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