Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 76
    Citation - Scopus: 82
    Multicolor Emitting Carbon Dot-Reinforced Pva Composites as Edible Food Packaging Films and Coatings With Antimicrobial and Uv-Blocking Properties
    (American Chemical Society, 2022) Alaş, Melis Özge; Doğan, Gamze; Yalçın, Mustafa Serkan; Özdemir, Sadin; Genç, Rükan
    Active food packaging has become attractive because of the possibility to provide a longer shelf-life by loading functional agents into the packages to maintain the quality of food products. Herein, photoluminescent and transparent polyvinyl alcohol (PVA)-based composites embedding multicolor fluorescent carbon dots (CD/PVA) were prepared by the solvent casting method. The prepared CDs emit a strong and stable fluorescence in solution while the CD/PVA composite films were transparent, flexible, and showed UV-blocking activity with a strong fluorescence emission. Blue color-emitting CDs showed the highest UV blockage at UVA (87.04%), UVB (87.04%), and UVC (92.22%) regions while PVA alone absorbed only less than 25% of the light in all UV regions. UV blockage capacity was shown to be decreased by half, in line with the emission color shift from blue to red. Thermal properties of the PVA film were improved by the addition of CDs to the polymer, and in vitro cell viability tests showed that none of the CDs were cytotoxic against the human lung fibroblast healthy cell line (MRC-F cells) when integrated into the PVA. The antimicrobial activity of CD/PVA nanofilms was qualitatively determined. The prepared films exhibited good antimicrobial activity against both Gram-positive and Gram-negative bacteria with mild antioxidant and metal chelating activity, and significant inhibition of biofilm formation with a strong link with emitted color and the concentration of the composites. Green- and red-emitting CD/PVA with the highest antimicrobial activity were then analyzed and compared with the plane PVA employing their effect on the shelf-life of strawberries as a model for perishable foods. Fresh strawberries dip coated with CD/PVA and PVA were monitored over time, and virtual evaluations showed that CDs/PVA film coating resulted in reduced weight and moisture loss and significantly inhibited the fungal growth and spoiling for over 6 days at RT and 12 days at fridge conditions maintaining the visual appearance and natural color of the fruit. The findings in this work indicated the potential of reported CD as non-cytotoxic, UV-blocking antimicrobial additives for the development of edible coatings and packages for their use in the food industry, as well as pharmaceutical and healthcare applications.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 17
    Characterization of Antimicrobial Activities of Olive Phenolics on Yeasts Using Conventional Methods and Mid-Infrared Spectroscopy
    (Springer, 2019) Canal, Canan; Özen, Banu; Baysal, Ayşe Handan
    Olive fruit is very rich in terms of phenolic compounds. Antimicrobial activities of various phenolic compounds against bacteria and fungi are well established; however, their effects on yeasts have not been examined. Aim of this study was to investigate the antimicrobial effects induced by olive phenolic compounds, including tyrosol, hydroxytyrosol, oleuropein, luteolin and apigenin against two yeast species, Aureobasidium pullulans and Saccharomyces cerevisiae. For this purpose, yeasts were treated with various concentrations (12.5-1000ppm) of phenolic compounds and reduction in yeast population was followed with optical density measurements with microplate reader, yeast colony forming units and mid-infrared spectroscopy. All phenolic compounds were effective on both yeasts, especially 200ppm and higher concentrations have significant antimicrobial activity; however, effects of lower levels depend on the type of phenolic compound. According to mid-infrared spectral data, significant changes were observed in 1200-900cm(-1) range corresponding to carbohydrates of yeast structure as a result of exposure to all phenolic compounds except tyrosol. Spectra of tyrosol and luteolin treated yeasts also showed changes in 1750-1500cm(-1) related to amide section and 3600-3000cm(-1) fatty acid region. Since phenolic compounds from olives were effective against yeasts, they could be used in food applications where yeast growth showed problem. In addition, FTIR spectroscopy could be successfully used to monitor and characterize antimicrobial activity of phenolic compounds on yeasts as complementary to conventional microbiological methods.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 18
    Synergistic Antimicrobial Effects of Activated Lactoferrin and Rosemary Extract in Vitro and Potential Application in Meat Storage
    (Springer Verlag, 2020) Soyer, Ferda; Keman, Deniz; Eroğlu, Erdal; Türe, Hasan
    This study aimed to explore the antimicrobial effects of activated lactoferrin (ALF) and rosemary extract (RE) on Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes, and to investigate their application potential in the meat storage. Minimum inhibitory concentrations (MICs) of ALF, RE and ALF-RE combinations were determined via microtiter plate assay. MICs of ALF were 1% for E. coli O157:H7; 0.5% for S. Enteritidis and 0.1% for L. monocytogenes. While 15% RE inhibited L. monocytogenes; 30% RE partially inhibited E. coli O157:H7 and S. Enteritidis growth. Synergistic effect of ALF and RE on the inhibition of E. coli O157:H7 increased the activity of ALF two to three folds. Food application of antimicrobials was performed by dipping of meat samples. Both ALF and RE were found effective in the prevention of L. monocytogenes growth about two logs. According to the data, choice of natural antimicrobials may be promising in food preservation.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 32
    Antimicrobial Activity of Tio2-Coated Orthodontic Ceramic Brackets Against Streptococcus Mutans and Candida Albicans
    (Springer Verlag, 2010) Özyıldız, Figen; Güden, Mustafa; Uzel, Ataç; Karaboz, İsmail; Akil, Övünç; Bulut, H.
    Polycrystalline alumina ceramic orthodontic brackets were coated with anatase TiO2 film via a sol-gel dip-coating method. The surface structure morphology and composition of the films were evaluated via scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The antimicrobial activity of the ceramic brackets was assessed against two oral pathogens, S. mutans and C. albicans. The results demonstrated that TiO 2-coated brackets exposed to low energy UV-A illumination efficiently reduced the populations of test microorganisms relative to the uncoated brackets. The reduction efficiencies were 98% for S. mutans ATCC 10449 and 93% for C. albicans ATCC 60193. © The Korean Society for Biotechnology and Bioengineering and Springer 2010.