Busra Polat’s research while affiliated with Erciyes University and other places

In this study some bioactive properties of extracts of wild pear (Pyrus elaegnifolia), hawthorn (Crataegus spp.), oriental hackberry (Celtis tournefortii), oleaster (Elaeagnus angustifolia), Japanese crabapple (Malus floribunda), rosehip (Rosa canina), pedunculate oak (Quercus robur), service tree (Sorbus domestica) and firethorn (Pyracantha coccinea) wildly growing in Turkey were investigated. The fruit extracts were analysed in terms of total phenolic content (TPC), antioxidant activities (DPPH and phosphomolybdenum methods) and antimicrobial activity. In the results, TPC, IC50 value of DPPH and IC50 value of phosphomolybdenum for pedunculate oak were 454.35 mg GAE/g d.w., 340.52 mg AAE/g d.w. and 96.52%, respectively. Service tree and firethorn exhibited the lowest TPC (4.11 mg GAE/g d.w.) and IC50 value of DPPH (53.32 mg AAE/g d.w.), respectively. Moreover, antimicrobial activity of oleaster was 2.46%. The hackberry fruit extract had no inhibitory effect against the tested microorganisms whereas pedunculate oak extract (with 10%) had the highest inhibitory effect against Aeromonas hydrophila. Additionally, all the fruit extracts had no antimicrobial activity against the Saccharomyces cerevisiae. In conclusion, wild edible fruit extracts can be used as bioactive material due to their antioxidant and antimicrobial activity in food industry and human nutrition.

In this study, bioactive (total phenolic, antioxidant and antiradical activity) and rheological properties (steady and dynamic) of rose hip marmalade were investigated. Bioactive properties were determined in rose hip marmalade and extract. Extract had higher total phenolic content (38.5 mg GAE/g dry extract), antioxidant activity (124 mg AAE/g dry extract) and antiradical activity (49.98 %) than marmalade. Steady and dynamic rheological properties of the marmalade were determined at different temperature levels (5, 25 and 45 °C). Rose hip marmalade exhibited shear thinning behavior and Ostwald de Waele model best described flow behavior of the sample (R 2 ≥ 0.9880) at different temperature levels. Consistency index and apparent viscosity values (η 50 ) at shear rate 50 s−1 decreased with increase in temperature level. Viscoelastic properties were determined by oscillatory shear measurements and G' (storage modulus) values were found to be higher than G'' (loss modulus) values, indicating that the rose hip marmalade had a weak gel−like structure with solid–like behavior. G', G'', G * (complex modulus) and η* (complex viscosity) values decreased with increase in temperature level. Modified Cox-Merz rule was satisfactorily applied to correlate apparent and complex viscosity values of the rose hip marmalade at all temperatures studied.

In the present study, we investigated the effects of four extracting solvents (70% acetone:water (v/v), 80% ethanol:water (v/v), 80% methanol:water (v/v) and distilled water) on the total phenolic content and antiradical, antioxidant activity and antimicrobial activities of extracts of myrtle berries (Myrtus communis) collected from eight different locations in Turkey. The tested plant extracts were found to contain appreciable amounts of total phenolic contents (39.933 to 207.4 mg GAE/g dry extract) and have 1.1-diphenyl-2- picrylhydrazyl scavenging activity ranging between 6.73 and 65.6%. The antioxidant activity of the myrtle fruits was measured using the phosphomolybdenum spectrophotometric method. The highest antioxidant activity value (241.533 mg ascorbic acid equivalents /g dry extract) was observed in the methanolic extract of the fifth sample. The agar diffusion method was used to determine the antimicrobial activity of the extract samples. It was found that the methanol and acetone extracts were more efficient against six pathogenic bacteria including Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium and Yersinia enterocolitica. The solvent systems used for extraction had an important effect on the bioactive compounds extracted. Based on the results, we conclude that myrtle berries can be considered as a good source of natural antioxidant and natural antimicrobial compounds.

This study was conducted to determine the potential use of anthocyanin-based extracts (ABEs) of wasted tulip flowers as food/drug colorants. For this aim, wasted tulip flowers were samples and analyzed for their bioactive properties and cytotoxicity. Total phenolic contents of the extracts of the claret red (126.55 mg of gallic acid equivalent (GAE)/g dry extract) and orange-red (113.76 mg GAE/g dry extract) flowers were the higher than those of the other tulip flowers. Total anthocyanin levels of the violet, orange-red, claret red and pink tulip flower extracts were determined as 265.04, 236.49, 839.08 and 404.45 mg pelargonidin 3-glucoside/kg dry extract, respectively and these levels were higher than those of the other flowers. The extracts were more effective for the inhibition of Listeria monocytogenes, Staphylococcus aureus and Yersinia enterocolitica compared to other tested bacteria. Additionally, the cytotoxic effects of five different tulip flower extracts on human breast adenocarcinoma (MCF-7) cell line were investigated. The results showed that the orange red, pink and violet extracts had no cytotoxic activity against MCF-7 cell lines while yellow and claret red extracts appeared to be toxic for the cells. Overall, the extracts of tulip flowers with different colors possess remarkable bioactive and cytotoxic properties.

Eremurus spectabilis grows in the spring as a wild vegetable and for many years has been used both as a food or food additive and for therapeutic purposes. This study investigated the total phenolic content and the antimicrobial, antioxidant, and antiradical activities of methanol, ethanol, and aqueous extracts of E. spectabilis (obtained from the Antalya region of Turkey). In addition, volatile compounds of E. spectabilis were characterized by using gas chromatography/mass spectrometry. Major components of E. spectabilis volatile compounds were carvone (44.64%), carvacrol (14.45%), pentane, 2-methyl- (7.34%), (E)-caryophyllene (5.57%), valencene (5.11%), cis-calamenene (2.01%), cadalene (1.10%), and acetic acid (1.12%). The highest total phenolic content was seen with methanol extract (mean±standard deviation, 31.92 ± 0.48 mg gallic acid equivalents/g dry extract). The ethanol extract showed the highest antiradical activity, with a 50% inhibitory concentration of 35.14 μg/L in the 1,1-diphenyl-2- picrylhydrazyl assay. The strongest antioxidant activity was detected in methanol extract (81.72 ± 0.62 mg ascorbic acid equivalents/g). Twelve bacteria species were used to analyze the antimicrobial activity of extracts. The 1% concentrations of all extracts showed no inhibitive effect on any bacterium. The most resistant bacterium was Yersinia enterocolitica, and the most sensitive bacterium was Pseudomonas aeruginosa. A positive correlation was seen between concentrations and inhibition zones, and some differences occurred between antimicrobial activity of other concentrations.