Browsing by Author "Cetinkaya, Turgay"

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Ambalajı Açıldıktan Sonra Buzdolabında Depolanan İki Farklı Tütsülenmiş Balık Ürününün Mikrobiyal Kalite Değişimlerinin Gözlenmesi
(2019) Cetinkaya, Turgay; Ceylan, Zafer
Günümüzde tütsülenmiş balık ürünleri tüketiciler tarafından yaygın olarak tercih edilmektedir. Ancak tütsülenmiş balık ürünlerindeözellikle ürünün ambalajı açıldıktan sonra mikrobiyal büyüme hızı artabilmektedir. Bu çalışma ile Türkiye'de büyük marketlerdesatılmakta olan iki farklı füme balık ürününün mikrobiyal değişimi 0., 12., 24., 36. ve 60. saatlerde izlenmiştir. Çalışmanın sonuçları,ambalajlar açıldıktan sonra buzdolabı koşullarında (4±1 ºC) saklanmasına rağmen füme balıklarında Toplam Mezofilik AerobikBakteri (TMAB), Toplam Psikrofilik Bakteri (TPB) ve Toplam Maya&Küf (TMK) yükünün hızlıca yükseldiğini göstermiştir. Buyüzden, çalışmanın sonuçlarına göre, ambalajların açılmasını takiben buzdolabı koşullarında saklanan füme Norveç Somonu (NS) veKaradeniz Alası (KA) örneklerinin 36. saatten sonra tüketilmemesi önerilmektedir. Çünkü 36 saat sonra, tütsülenmiş NS ve KA içinTMAB yükü sırasıyla 5.49 log KOB/g ve 5.95 log KOB/g değerlerine ulaşmıştır. TPB yükü ise tütsülenmiş NS ve KA örneklerindesırasıyla 6.11 KOB/g ve 6.02 KOB/g, olarak belirlenmiştir. Bu örneklerde TMK değerlerinde de yükselme olmasına rağmen budeğerlerin bakteriyel gelişmeye göre daha düşük olduğu tespit edilmiştir. Ancak 36 saat içinde, KA ürünlerinde TMK değerinin 5 logKOB/g’ın üzerine çıktığı görülmüştür. Öte yandan, 36. saatte NS ürünlerinin TMK değerinin ise 5 log KOB/g’dan daha az olduğubelirlenmiştir. Ayrıca, NS ve KA ürünlerinde duman aromasınının 24 saat sonunda kısmen kaybolduğu ve bazı bölgelerde örneklerinrenginin değişerek yeşillenmeye başladığını gözlemlenmiştir. Bütün sonuçlar birlikte değerlendirildiğinde, özellikle tütsülenmiş balıkürünlerinin ambalajı açıldıktan sonra, ilk 24 saat içinde tüketilmesi tavsiye edilmektedir. Bu çalışma, tütsülenmiş balık ürünlerindemikrobiyal bozulmayı önlemek için duman aromasını raf ömrü boyunca ambalaj içinde tutacak özelliklere sahip ambalaj kullanılmasıgerektiğini göstermiştir. Buna ilaveten ambalaj içindeki balığın bozulma durumunu gösteren, bozulma sürecini geciktiren akıllıve/veya aktif ambalaj uygulamaları üzerinde de çalışılması gerekmektedir.
Application of Cold Plasma Technology in the Food Industry and Its Combination With Other Emerging Technologies
(Elsevier Science London, 2021) Ucar, Yilmaz; Ceylan, Zafer; Durmus, Mustafa; Tomar, Oktay; Cetinkaya, Turgay
Background: The search for preservation methods that can be used as alternatives to heat treatment is a significant issue in food quality. Utilization of plasma technology, a useful nonthermal technique, is encouraged in the food industry because of its effectiveness in preserving the natural aroma and flavor and antimicrobial activity. Scope and approach: The cold plasma (CP) technique is used for food processing for enhancing antimicrobial activity, structural modification, decontamination of surfaces, and disinfection of food-processing instruments. Currently, a combination of CP with other promising approaches, such as nanotechnology applications, including nanofiber, nanoemulsion, nanoparticles, and nanoencapsulation, and emerging nonthermal technologies, including pulsed electric field (PEF), pulsed light (PL), and ultrasound, is gaining increased attention. In addition to its many advantages, CP is a low-cost method that can be an alternative to heat-based techniques used for the processing of food products. Therefore, application of CP technology in the food industry has been described in this review. Key findings and conclusions: Demand for raw or non-heat-treated foods is increasing due to factors, such as the preference of consumers for healthy foods and the development of consumer awareness. However, plasma technology can be used to improve microbial quality and prevent rapid physical, chemical, and sensory changes. Studies have shown that CP application is effective in offering higher-quality products for consumption by extending the shelf life of foods. Positive results have been achieved in terms of both quality and microbial activity in different food groups with plasma technology. In addition to recently published articles, the combined hurdle effect of CP with other emerging novel technologies such as nanotechnology, pulsed electric field (PEF), pulsed light (PL), and ultrasound processing on food or food packaging materials could be further studied and used to ensure food safety. However, the high initial investment costs for CP need to be considered.
Definition of Textural Deterioration in Squid Samples: Three Different Tools Supported by Microbial, Visual and Physico-Chemical Analysis
(Ege Univ, Fac Fisheries, 2021) Ceylan, Zafer; Cetinkaya, Turgay
The aim of the present study was to reveal the textural profile changes like hardness, cohesiveness, springiness, and adhesion supported by total mesophilic aerobic bacteria count (TMABc), pH, and some visual sensory characteristics in squid samples stored at 4 degrees C. Three different Brookfield Texture Analyzer tools, named TA7, TA9, and TA18 were used to observe the textural changes more clearly. The difference of TMABc between the storage days reached from 4.32 log CFU/g to 6.32 log CFU/g. The hardness value of the squid samples, detected by TA18 and TA9 tools, increased while the hardness value obtained from TA7 was higher. The highest change in cohesiveness value in the squid samples was defined by the TA9 tool as similar to 63%. Once springiness values detected by TA9 were sharply decreased from 4.9 mm to 2.1 mm, those of TA7 and TA18 were slowly decreased. The most increase in adhesion value (0.08 mJ to 0.21 mJ) was obtained in the TA7 tool. Depending on the textural quality changes, the pH value was increased, and as visual and sensory, dark, or yellow spots were observed. The present study results revealed that especially the TA18 tool could be effectively used to determine the quality changes of the squid samples.
Depolama Süresince Balıketi Kalitesinde Meydana Gelen Değişimlerin Hızlı ve Yenilikçi Metotlarla Belirlenmesi
(2021) Altay, Filiz; Cetinkaya, Turgay; Ceylan, Zafer
Farklı üç balık türünün (yerli somon: YS, çipura: Ç, levrek: L) et kısımlarında yapılan analizler ile literatürde fazlayer almayan ve nadir çalışılan bazı fiziksel parametreler yardımıyla balıketlerinin kalite değişimleri 0. 2. ve 4. günlerdeincelenmiştir. Bu bağlamda, örneklere ve depolamaya bağlı değişmekle birlikte, elektriksel iletkenlik değeri (mS $cm^{-1}$ )%9.52 ile %104 arasında artış göstermiştir. Yüzey gerilimi değeri ise depolama süresinin artışına bağlı olarak azalmıştır. Çörneklerinde bu değer 42.56 mN m-1’den hızlıca azalma göstererek depolamanın ikinci gününde 16.20 mN $m^{-1}$ ’e kadardüşmüştür (p<0.05). Dielektrik kayıp faktörü (ε″) ise tüm örneklerde, analiz periyoduna bağlı olarak artış göstermiştir.Duyusal değerlendirme sonuçlarına göre Ç ve L örnekleri ikinci gün itibari ile tüketilemez olarak kabul edilirken buörneklerin dielektrik kayıp faktörünün sırası ile 419.72’den 491.07’ye ve 408.21’den 430.7’ye arttığı gözlenmiştir. Öteyandan partikül boyutu (PB) ve polidispersite indeks (PDI) değerleri ile anlamlı bir sonuç elde edilememiştir. Yaygın olarakkullanılan pH analizi sonuçları ise yüzey gerilimi ve elektriksel iletkenlikteki değişimleri doğrular nitelikte bulunmuş olup,depolama süresinin artışına bağlı olarak pH değerleri artış göstermiştir. Bu çalışmanın sonuçları, kısa sürede bozulabilenürünlerin farklı ve hızlı yenilikçi analiz yöntemleri ile kalitelerinin başarılı bir şekilde ortaya konulabileceğini göstermiştir.Ayrıca diğer çalışmalar ve gıda işleme sektörü için rehber değeri taşıyan bir çalışma ortaya konulmuştur.
Development of Kafirin-Based Nanocapsules by Electrospraying for Encapsulation of Fish Oil
(Elsevier, 2021) Cetinkaya, Turgay; Mendes, Ana C.; Jacobsen, Charlotte; Ceylan, Zafer; Chronakis, Ioannis S.; Bean, Scott R.; Garcia-Moreno, Pedro J.
Kafirin-based fish oil nanocapsules were successfully obtained by using electrospraying technique. A kafirin isolate containing mostly alpha-kafirins, but also gamma- and beta-kafirins, was used as shell material. Electrospraying solutions with 10 wt% kafirin and fish oil (20 wt% with respect to kafirin) led to the production of nanocapsules (552 and 861 nm) when electrosprayed at 20-25 kV voltage with flow rates ranging from 0.5 to 1 mL/h. Neither the flow rate nor the voltage had a significant effect (p > 0.05) on the average diameter of the kafirin electrosprayed capsules loaded with fish oil. The encapsulation efficiency of the nanocapsules was up to 94.0 +/- 2.5%, indicating that most of the fish oil was encapsulated within the kafirin shell. These results suggest the feasibility of obtaining kafirin-based capsules for the encapsulation of fish oil by electrospraying. This will open up new possibilities for kafirin as hydrophobic shell material for the production of fish oil encapsulates, which can be applied to the fortification with omega-3 fatty acids of food matrices.
Fabrication and Characterization of Zein Nanofibers Integrated With Gold Nanospheres
(Elsevier, 2022) Cetinkaya, Turgay; Wijaya, Wahyu; Altay, Filiz; Ceylan, Zafer
The synthesis, characterization, and coating effect of zein nanofibers integrated with gold nanospheres were studied. Zein solution including ethanol/liquid gold nanospheres (80/20 v/v) was prepared to produce complex nanofibers. Dielectric constant (epsilon '), dielectric loss factor (epsilon ''), and loss tangent (epsilon ''/epsilon ') values of feed solutions were evaluated at 300 and 3000 MHz, and electrical conductivity was measured (808.67 +/- 2.082 mu s/cm). SEM image showed a bead free structure of the gold-zein complex. Zeta potential and DLS measurements (translational diffusion coefficient, hydrodynamic radii, polydispersity index, major axis) were done by dispersing nanofibers in ethanol or water. The stability of nanofiber dispersed in ethanol was higher (+41.73 mV) compared to that of dispersed in water (+5.1 mV). Molecular characterization by FTIR confirmed the formation of the zeingold complex through a nitrogen-gold coordination bond and electrostatic interactions. The gold-zein nanofibers coating in sea bream fillets reduced 17.8% of total mesophilic bacteria (TMAB) compared to the uncoated group (p < 0.05) after 8 days of observation. The highest changes in epsilon ' for uncoated (57.65%) and coated samples (14.84%) during storage showed the positive impact of nanofiber treatment. These results showed that zein nanofibers with gold nanospheres could be potentially used as antimicrobial layer for food products.
A New Application With Characterized Oil-In Double Emulsions: Gelatin-Xanthan Gum Complexes for the Edible Oil Industry
(Elsevier, 2021) Cetinkaya, Turgay; Altay, Filiz; Ceylan, Zafer
A novel oil-in-water-in-oil (O-1/W/O-2) double emulsion (DE) system was successfully created to decrease the saturated fat content. DEs stabilized with gelatin (GL), xanthan gum (XG), and solid fat crystals were generated using a two-stage emulsification process. Primary emulsions (PEs) containing 60 g/100 g and 20 g/100 g sunflower oil (SFO) were prepared with constant GL (at 1 g/100 g) and XG (at 0.6 g/100 g and 1.4 g/100 g) of the total emulsion, respectively. DEs at constant water concentrations containing SFO at 30, 38.3, 46.7, and 55 g/100 g and different water concentrations at 30, 40, 45, and 60 g/100 g were examined. The DE microstructure showed that SFO was encapsulated in internal water droplets, which were stabilized by interfacial accumulation of fat crystals. The hardness value of the DEs decreased from 13.40 to 3.42 N with increasing SFO. Amplitude and frequency sweep tests revealed a weak gel structure and elastic behavior of DEs. In addition, a decrease in gel stiffness was observed with an increase in SFO and water content. The results of the present study effectively demonstrated a new approach applicable for the edible oil industry, formulating O-1/W/O-2 DEs using a natural emulsifier (GL) and a stabilizer (XG).
A Novel Strategy for Au in Food Science: Nanoformulation in Dielectric, Sensory Properties, and Microbiological Quality of Fish Meat
(Elsevier, 2021) Cetinkaya, Turgay; Ceylan, Zafer; Meral, Raciye; Kilicer, Ali; Altay, Filiz
Fabrication of Au-zein-based nanomats (AuZ-Nm) was successfully carried out by using the electrospinning technique. The average diameters of Au were found as 530 +/- 377 nm within zein nanomats having 161 +/- 45 nm. The nanomats were used to delay the Total Mesophilic Aerobic Bacteria (TMAB) growth in the skinless fish fillets stored at 4 +/- 1 degrees C. Besides control samples, dielectric properties (epsilon' and epsilon '') of the skinless fish fillets treated with AuZ-Nm were revealed. During the 8-days-storage, sensory changes in the samples treated with AuZ-Nm were determined. Microbiological test demonstrated that the use of AuZ-Nm limited the TMAB growth up to similar to 1 log CFU/g (p < 0.05). epsilon' values of the fish samples treated with AuZ-Nm (changes from 76.47 to 54.29) were more stable as compared to untreated fish samples (p < 0.05). The changes in epsilon '' for control and nanotreated samples were 86.94% and 77.92%. The overall acceptability of the nanotreated samples was higher than the control samples. The stability of dielectric properties, limitation of microbiological spoilage, and also delaying of sensory deterioration of the fish fillets could be provided by using AuZ-Nm. In this respect, the use of Au-zein-based nanomats in the present study with the results could be playing a guiding role for further food studies.