Chitosan films incorporated with thyme oil for potential applications of wound dressing were successfully prepared by solvent casting method. The water vapor permeability, oxygen transmission rate, and mechanical properties of the films were determined. Surface and crosssection morphologies and the film thicknesses were determined by Scanning Electron Microscopy (SEM). Fourier transform infrared (FT-IR) spectroscopy was conducted to determine functional group interactions between the chitosan and thyme oil. Thermal behaviors of the films were analyzed by Thermal Gravimetry (TGA) and Differential Scanning Calorimetry (DSC). In addition, the antimicrobial and the antioxidant activities of the films were investigated. The antimicrobial test was carried by agar diffusion method and the growth inhibition effects of the films including different amount of thyme oil were tested on the gram negative microorganisms of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and a gram positive microorganism of Staphylococcus aureus. The minimum thyme oil concentration in chitosan films showing the antimicrobial activity on all microorganisms used in the study was found as 1.2 % (v/v). In addition, this concentration showed the highest antioxidant activity due to mainly the carvacrol in thyme oil. Water vapor permeability and oxygen transmission rate of the films slightly increased, however, mechanical properties decreased with thyme oil incorporation. The results revealed that the thyme oil has a good potential to be incorporated into chitosan to make antibacterial and permeable films for wound healing applications.

General objective of the present work was to assess the isolation of polyphenols from olive leaves. The effects of extraction conditions on the total phenol content and antioxidant activity of olive leaf extract (OLE) were investigated. An extract with good antioxidant activity (7.52 mmol of Trolox equivalent antioxidant capacity (TEAC)/g olive leaf extract), and a high content of oleuropein (13.4%) and rutin (0.18%) could be obtained using 70% ethanol as extraction solvent. There was a good correlation between the antioxidant activity and the total phenol content. Furthermore, silk fibroin was used as a novel adsorbent to recover the polyphenols from the olive leaf extracts. The adsorbed amounts of rutin and oleuropein were 15 mg rutin/g silk fibroin and 96 mg oleuropein/g silk fibroin. Fraction consisting of mainly oleuropein and fraction rich in rutin, luteolin-7-glucoside, verbascoside, apigenin-7-glucoside were obtained by using silk fibroin filled column. Silk fibroin was found to be a promising adsorbent for the purification of oleuropein and rutin from olive leaf extracts.

The adsorption isotherms of oleuropein and rutin were evaluated at different temperatures, pH values, and solid/liquid ratios. The experimental data of adsorption isotherms were well fitted to a Langmuir model. The maximum adsorption capacities were determined as 108 mg of oleuropein/g of silk fibroin and 21 mg of rutin/g of silk fibroin. After adsorption of oleuropein and rutin, the antioxidant capacity of silk fibroin increased from 1.93 to 3.61 mmol of TEAC/g. Silk fibroin also gained antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae after adsorption of olive leaf antioxidants. In a desorption process, 81% of rutin and 85% of oleuropein were removed from the adsorbent surface in 70% aqueous ethanol solution. Consequently, silk fibroin was found to be a promising biomaterial for the production of functional food or dietary supplements and for the purification of oleuropein and rutin from olive leaf extracts.

a b s t r a c tIn this study, inhibition of Escherichia coli glucuronidase (GUS) by a plant extract of Pistacia terebinthus was investigated. P. terebinthus (from Karaburun region in Turkey) leaf extract exhibits various bioactivities, such as antioxidant, antimicrobial and cytotoxic property because of its flavonoid, phenolic and alkaloid contents. HPLC analyses were performed to evaluate the composition of the extract and main flavonoid compounds such as luteolin, luteolin-7-glucoside and apigenin-7-glucoside were detected in extract. GUS activity and kinetic data of the GUS were obtained by measuring rate of production of resulting fluorescent 4-methylumbelliferone (4-MU) and phenolphthalein fluorometrically and spectrophotometrically, respectively. Plant leaves showed higher antioxidant capacity as 85 TEAC (trolox equivalent antioxidant capacity) value and higher antimicrobial activity towards Staphylococcus aureus. 92.4% GUS enzyme inhibition was achieved with 8.3 g ml −1 crude extract concentration, where IC 50 value was found as 2.1 (±0.2) g ml −1 . Kinetic studies by nonlinear regression revealed that inhibition type caused by plant extract was mixed type (noncompetitive and competitive together). K m and V max values were 96.94 ± 9.68 nM and 7.81 ± 0.16 nmol min −1 mg −1 , respectively. Inhibition constant (˛K i ) was found as 7.00 ± 0.93 nM having˛value 2.17 ± 0.93. Our results may provide useful information regarding the inhibition of microbial GUS activity, preventing deglucuronidation and reducing possible cancer risk by bioactive P. terebinthus crude extract.

Tartaric acid is mainly used in food, pharmaceuticals and cosmetics industries. In this study, the waste samples, which contain tartaric acid, from the wastes of wine and grape juice industries were characterized by using TG, DSC, FTIR and XRD techniques. HPLC was used to determine tartaric acid content of samples. The decomposition temperatures of waste samples were found to be relatively higher compared with that of pure tartaric acid. This difference in decomposition temperatures was attributed to the presence of potassium tartrate since high potassium content was detected with ICP-AES.Kuzenler Export & Import Ltd. Co

In the present study, “sweet pomegranate pekmez” (PP), was produced by three different methods as open pan evaporation (OPE), application of activated carbon prior to open pan evaporation (AC), and vacuum evaporation (VE). The effects of activated carbon treatment and production methods on pH, density, soluble solids, water activity, total phenolic content, HMF formation, mineral content, and texture characteristics were investigated. Textural properties of PP increased with increasing soluble solids content. HMF was not detected in AC and VE products. HMF content of OPE product was measured as 2.77 ± 0.28 mg.100 g. Activated carbon treatment resulted in significant reductions in mineral, HMF, and TPC contents of pekmez samples. HMF formation kinetics of PP was investigated at various accelerated storage temperatures. HMF formation was well described by the zero‐order reaction model among five kinetic models applied. The rate of reaction was determined as highly temperature‐dependent by an Arrhenius equation. Practical applications In recent years, consumer interest and demand for potentially health‐promoting products has motivated the production of such food products. In this context, in this study, sweet pomegranate pekmez is introduced as a potentially healthy product produced by different methods, and the production stages and conditions that may enlighten the industrial production of this traditional product are provided. In addition, the application of activated carbon used in the production of pekmez has been presented as an alternative method to reduce the potential formation of HMF during heat treatment.

Özetçe (3,5,, bazı bitkilerde bulunan fenolik bir bileşen olup antioksidatif, antikanserojenik ve antitümör özellikleri bildirilmiştir. Ancak bu madde UV ışığına maruz kaldığında -cis formuna dönerek biyoaktivitesini kaybettiği bilinmektedir. Bu çalışma, transresveratrolün kitosan mikrokürelere yüklenerek kararlılığını arttırmayı hedeflemektedir. Bu kapsamda püskürtmeli kurutma yöntemiyle trans-resveratrol içeren kitosan mikroküreler üretilmiş ve karakterize edilmiştir. Mikrokürelerin parçacık boyutu ve yüzey morfolojisi taramalı elektron mikroskopuyla (SEM), termal özellikleri ise termogravimetrik analizörüyle (TGA) incelenmiştir. trans-resveratrol'ün serbest ve mikroküre içerisindeki kararlılığı yüksek performans sıvı kromatografisiyle (HPLC) incelenmiştir. Bu analizle kitosan mikrokürelere yüklenen trans-resveratrolün stabilitesini koruduğu saptanmıştır.Abstract (3,5,, a phenolic compound present in some plant species, have been shown to posses antioxidative, anticarcinogenic and antitumour properties. However, under UV light, it turns into -cis form and looses its bioactivity.This study aims to increase the stability of trans-resveratrol by loading it into chitosan microspheres. Within this context, the trans-resveratrol loaded chitosan microspheres was produced by spray drying and then the resultant microspheres were characterized. The particle size and the surface morphology of resultant microspheres were investigated by scanning electron microscope (SEM) and the thermal properties were determined by thermogravimetry analyser(TGA). The stability of free and that of inside the microspheres was determined by high performance liquid chromatography (HPLC). It was found that the stability of trans-resveratrol incorporated into chitosan microspheres kept constant. Giriştrans-Resveratrol, C 14 H 12 O 3 , bitkiler tarafından mikrobik, fungal ve fiziksel uyaranlara karşı üretilen antimikrobiyal ve antifungal etkili bir fitoaleksindir. cis ve trans izomerleri vardır ancak trans formu daha yaygın ve biyolojik olarak daha aktiftir [1]. Şekil 1: trans-resveratrol'ün kimyasal yapısı [2] trans-Resveratrol üzüm, ahududu, dut, yabanmersini, kızılcık, yer fıstığı ve bazı çam ağaçlarında bulunmakla birlikte üzüm ve üzümden üretilen ürünler bu maddenin en önemli besinsel kaynaklarıdır. Bu madde üzümde mikrobiyal enfeksiyon, herbisit ve fungisit gibi kimyasal uygulamalar ile stres ve UV ışığına maruz kalma sonucunda sentezlenir. cis-Resveratrol üzümün doğal bir bileşeni değildir. Ancak orijin ve uygulanan teknolojiye bağlı olmaksızın incelenen hemen hemen bütün şaraplarda tespit edilmesi, bu maddenin şarap üretimi esnasında trans izomerinden cis izomerine dönüştüğünü göstermektedir [2]. trans-Resveratrol çoğunlukla damar tıkanıklığının tedavisinde ve yüksek kolesterolün düşürülmesinde kullanılır. Bununla birlikte, antiviral ve antiinflamatuar aktivitesi akut mikrobiyal enfeksiyonların ve hepatitin tedavisinde kullanımına olanak sağlar. Bazı bulgular Herpes Simplex ve HIV gibi retrovirüslerle mücadeleyi güçlendirdiği görüşünü de...

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