Ezine Meslek Yüksekokulu Koleksiyonu

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https://hdl.handle.net/20.500.12428/3543

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Yayıkaltı içeceğinin fizikokimyasal ve duyusal özellikleri ile uçucu bileşenlerinin belirlenmesi
(2021) Öğe, Çisem; Karagül Yüceer, Yonca
Bu çalışmada yayıkaltı suyunun farklı mikroorganizmalarla fermantasyonu ile üretilen içeceklerin karakteristik bazı özelliklerinin belirlenmesi amaçlanmıştır. Toz halindeki yayıkaltının %10’luk çözeltisi ile belirli oranlarda (% 0, 25, 50, 75, 100) çiğ süt karışımına ısıl işlem uygulandıktan sonra örneklere L. acidophilus (LA) kültürü ve L. acidophilus, Bifidobacteria ile S. thermophilus karışık kültürü (ABT) ilave edilerek 37°C’de, yaklaşık 4.8 pH’ya kadar inkübe edilmiştir. Ürünlerin fizikokimyasal ve duyusal özellikleri ve uçucu bileşenleri depolama süresince belirlenmiştir. İçeceklerde yayıkaltı suyu oranı azaldıkça yağ, kurumadde ve protein oranları artmıştır. Örneklerde uçucu bileşenler gaz kromatografisi kütle spektrometrisi kullanılarak belirlenmiştir. Tüm örneklerde belirlenen uçucu bileşikler aseton, 2,3-butandion, asetoin, toluen, 2-heptanon, limonen, ökaliptol, asetik asit ve butanoik asit olmuştur. Yayıkaltı içeceklerinde pişmiş, kremamsı, süthane/sütümsü, fermente, karton, yosun, sabunsu, depo, tatlı, tuzlu, buruk ve acı terimleri duyusal değerlendirmeler sonucunda belirlenmiştir.
Preparation and characterization of glycerol monostearate and polyglycerol stearate oleogels with selected amphiphiles
(Elsevier Ltd, 2021) Keskin Uslu, Eda; Yılmaz, Emin
This study aimed to prepare and compare sunflower oil oleogels with glycerol monostearate (GMS) and polyglycerol stearate (PGS) organogelators. Also, GMS oleogels with Pluronic F68 (F68) and Span 80 (SP80) amphiphiles, and PGS oleogels with Pluronic F68 and Tween 60 (TW60) amphiphiles were prepared to evaluate the effects of amphiphiles on oleogel properties. Minimum gelation concentration, gelation time, oil binding capacity, instrumental color, thermal properties, microscopy, X-ray diffraction patterns, and rheological properties were measured. Results indicated that the addition of the amphiphiles reduced minimum gelation concentration, increased crystals size, enhanced gelation time, changed color values, and reduced melting temperatures. Further, amphiphile addition yielded more stable but softer textures. All samples were thermo-reversible and stable during storage. New data for food-grade PGS oleogels were provided for the literature. PGS oleogels were found as good as GMS oleogels in most properties. Future studies with the prepared oleogels for various applications, including food products are envisioned.
Carbapenem resistance and biofilm formation status of Enterobacterales isolated from raw milk via molecular versus phenotypic methods
(Springer Science and Business Media Deutschland GmbH, 2023) Özdikmenli Tepeli, Seda; Tosun, Melike Nur; Taylan Yalçın, Gizem; Kaya, Burcu; İpek, Dilvin; Zorba, Nükhet Nilüfer
Antibiotic resistance genes can easily be transferred between bacteria in the biofilm. In the dairy industry, many bacterial species forming biofilms on the surfaces of equipment are widely reported. The experiments reported in this research paper aimed to investigate the carbapenem resistance and biofilm formation properties of Enterobacterales isolates which are spoilage microorganisms obtained from raw milk. In addition, the study determined that whether there was a relationship between the biofilm formation ability or the protein spectra of these isolates. In this study, ninety-two Enterobacterales isolates collected from 173 raw milk samples were investigated. Initially, the isolates were identified as Citrobacter braakii (n = 18), Citrobacter freundii (n = 12), Enterobacter asburiae (n = 1), Enterobacter cloacae (n = 3), Escherichia coli (n = 10), Hafnia alvei (n = 18), Klebsiella oxytoca (n = 1), Serratia fonticola (n = 24), Serratia liquefaciens (n = 4), and Serratia marcescens (n = 1) using MALDI-TOF MS. As a result, carbapenem resistance was determined in 6.5% of the isolates by CIM test, MHT, and the disk diffusion methods, but none of them had blaOXA-48, blaKPC, blaNDM-1, blaOXA23, blaOXA-58, blaOXA-51, blaVIM, and blaIMP genes. This may be due to the effect of other resistance mechanisms such as porin loss or increased flow pump activity. Furthermore, biofilm formation (weak and moderate) was detected in 97.8% of the Enterobacterales isolates. The mass spectra of the moderate biofilm producer isolate of Serratia spp. and the mass spectra of the weak biofilm producers of E.coli presented similarities.
Preparation and characterization of oleogels and emulgels with glycerol monooleate–cholesterol mixtures
(Springer, 2021) Keskin Uslu, Eda; Yılmaz, Emin
This study aimed to prepare and characterize oleogels and emulgels with glycerol monooleate (GMO): cholesterol gelator system. Oleogels, including 5 and 10% of each gelator were prepared. Emulgels with the same organogelator mixture concentrations, and 10 and 20% water phase were also prepared successfully. The gelation time decreased as the added gelator mixture and water concentrations increased. All samples had signifcant oil binding capacity and creamish-white colors. The oleogels melted just below body temperature, while emulgels melted around body temperature as determined by diferential scanning calorimetry. The samples’ crystalline networks were observed with the X-ray difraction analysis and displayed β and β′ polymorphic type crystals. Rheological measurements revealed that as gelator mixture concentration increased, gel strength enhanced, but in the emulgels, the gel strength decreased signifcantly as added water content increased. All oleogels and emulgels showed time-dependent thixotropic recovery ability. Temperature ramp tests indicated that the oleogels were stable up to 28 °C, but the emulgels kept their gelled consistency up to 70 °C. Overall, the common properties of these new oleogel and emulgels were provided. Future studies for some applications are foreseen.
Sunflower Oil-Beeswax Oleogels Are Promising Frying Medium for Potato Strips
(Wiley, 2021) Aydeniz Güneser, Buket; Yılmaz, Emin; Keskin Uslu, Eda
Sunflower oil-beeswax oleogels at 3% (BWO-3) and 8% (BWO-8) organogelator concentration are prepared to evaluate oleogels as frying medium for potato strip frying against commercial sunflower oil (SO). Rheological and thermal analyses of oleogels prove that the samples are fully solid (20 +/- 3 degrees C) and totally liquid (180 degrees C), and thermoreversible. Fresh and used (after frying) fat analyses show that free fatty acidity (FFA), peroxide value (PV) and total polar materials (TPM) are enhanced in all samples at the 7th h, but the relative enhancement levels are lower in oleogel samples. Potato strips fried in oleogels absorb significantly less oil (11.97% and 12.07%) than the control sample (15.20%). Potatoes fried in oleogels are also more bright and yellower than the control sample. Textural profile of the fried potatoes indicates that the samples fried in oleogels are harder, springier, and gummier than that of the control sample. Sensory analysis shows that oleogel fried potatoes get higher sensory scores. Also, overall acceptability of potatoes fried in BWO-8 sample is the highest (8.50) among all. The prepared oleogels are found quite promising frying medium in this study. Further studies with other types of oleogels in extended period frying of various foods are suggested. Practical applications: The development of innovative frying techniques to produce healthier products with lower fat and calorie values are still a remarkable research area. Oleogelation is an emerging strategy used for solid-like oil designing and based on the formation of 3D networks by the addition of organogelators. Oleogelation is accepted as a healthy strategy to structure liquid oils into solid consistency, and oleogels have great edible applications in processed foods, and can be used as a frying medium. This work can guide the use of sunflower oil-beeswax oleogels as a frying medium and allow the development of more healthy fried snacks.
Distribution, sources and ecological risk assessment of metals in Kura river sediments along a human disturbance gradient
(Taylor and Francis, 2021) Kukrer, Serkan; Tunc, I. Onur; Erginal, Ahmet Evren; Bay, Ozender; Kilic, Seref
Monitoring the pollution status of freshwater resources is an important step in sustainable planning. This study aimed to determine the distribution and sources of metals in the sediments of the transboundary eastern Anatolian/Caucasus region Kura river as well as its ecological risk level. Surface sediment samples were collected from eight sites along the human disturbance gradient. Multi-element analyses of the collected samples were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chlorophyll degradation product (CDP) analysis was performed spectrophotometrically. OC analysis was carried out using the titration method. The data obtained were evaluated using the indices of enrichment factor, geo-accumulation, modified hazard quotient and ecological contamination index and potential ecological risk. The average content of metals in the sediment at the eight sites was of the following descending order from highest to lowest: Al > Mn > Zn > V> Ni > Cr > Cu > Co > Pb > As > Cd > Tl > Hg. According to the distribution of raw metal values, urbanization is not the only factor controlling metal distribution. Adsorption processes and organic material content also emerge as an important factor. Enrichment factor values were of the following order: T1 > Pb > Mn > Hg > Cr > Co > Cd > Ni > As > Zn > Al > Cu > V. Results revealed that the sources of Cu, V and Al were lithogenic, in contrast to Tl, Pb, Mn, Hg, Cr, Co, Cd, Ni, and As, thus pointing to human-induced accumulation. According to the potential ecological risk index, these elements have the potential to create medium-to-high level ecological risks and were substantially of atmospheric origin. The ecological contamination index is also consistent with these findings in terms of risk level. A municipal waste stream, fossil fuel burning and a cement plant operating in close proximity also appeared to be the possible sources.
Oleogels of Some Plant Waxes: Characterization and Comparison with Sunflower Wax Oleogel
(Wiley, 2021) Yılmaz, Emin; Keskin Uslu, Eda; Öz, Ceren
This study aimed to develop the oleogels of teawax (TWO), rapeseed wax (RWO), orange peel wax(OWO), rose wax (RsWO), and beery wax (BWO), and tocompare their properties with sunflower wax oleogel(SWO). Since the literature lacks most of these newoleogels, the gained information would be valuable. Thewax oleogels were analyzed for their main physicochemi-cal, thermal, structural, rheological, and sensory properties.The minimum gelation concentrations (C*) ranged from1.0% (SWO) to 25% (RWO), with gelation times of0.3–205 min, respectively. While polarized light micros-copy images showed large crystal aggregates, X-ray dif-fraction patterns proved the presence ofβ ́ polymorphcrystals and some amorphous solids. Rheological analysesindicated that the samples had a weak-gel structure, andwere stable until around 30–70 C temperatures. Further,the oleogel samples showed a thixotropic rheologicalbehavior with force-related recovery at 10 C. Quantitativesensory descriptive analysis (QDA) proved that there weresome differences among the samples for sensory hardness,spreadability, liquefaction, rancid, waxy, and cooling attri-butes. Also, tea aroma in TWO, bitterness in OWO, androse aroma in RsWO were quite dominant. In conclusion,RWO and OWO seemed unsuitable for food applicationsdue to very high C* and bitterness, while RsWO and BWOcould be used in food formulations.
Kurumsal Eşbiçimlilik Kapsamında Havayolu İttifaklarının Misyon İfadelerinin İncelenmesi
(Çanakkale Onsekiz Mart Üniversitesi, 2018-11-29) Çavuşgil Köse, Bilge; Erden Ayhün, Sena
Yönetim bilimi yazınında önemli bir kavram olarak yer bulan kurumsal eşbiçimlilik, örgütleri birbirine benzer kılan nedir sorusundan hareketle bir birimin aynı çevresel koşullarda yer aldığı diğer birimlere benzemesine neden olan kısıtlıyıcı bir süreç olarak tanımlanmaktadır. Kurumsal eşbiçimlilik; örgütler arasındaki güç ve yaptırım farklarından kaynaklanan zorlayıcı kurumsal eşbiçimlilik, uzman olarak kabul edilen örgütlerin kopyalanması ile oluşan taklitçi kurumsal eşbiçimlilik ve alanda yer alan kural, yasa ve standartların ortaya çıkardığı normatif kurumsal eşbiçimlilik olmak üzere üçe ayrılmaktadır. Havayolu ittifakları küresel havacılık endüstrisinin temel unsurlarından olup küresel havayolu pazarında önemli bir rol üstlenmektedirler. İlgili yazında hem popüler bir işletme stratejisi olarak küresel havayolu ittifakları kavramını hem de etkili stratejik yönetim bağlamında işletmelerin misyon ifadelerinin önemini ayrı ayrı inceleyen pek çok araştırma bulunmaktdır. Bu araştırma ile öncelikle havacılık endüstrisi açısından ideal bir misyon bildirgesinde yer alması gereken hususların belirlenmesi planlanmaktadır. Bu kapsamda küresel bir havayolu ittifakının içinde yer alan 27 uluslararası havayolu firmasının misyon ifadeleri Pearce ve David (1987)’ in belirlediği kapsamlı bir misyon beyanatının dokuz bileşeni doğrultusunda içerik analizine tabi tutulacaktır. Daha sonra söz konusu misyon ifadelerinin kurumsal eşbiçimlilik kapsamında incelenmesi amaçlanmaktadır. Araştırma sonuçlarının turizm ve seyahat endüstrisinin önemli bir kolu olan havacılık sektöründe stratejik yönetim hususunda katkı vereceği düşünülmektedir.

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