Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Conference Object Does Locoregional Treatment in De Novo Stage Iv Bone-Only Metastatic Breast Cancer Prolong Survival? an Ongoing Multicenter Registry Study(Elsevier, 2019) Soran, Atilla; Işık, Arda; Doğan, Lütfi; Sezgin, Efe; Özbaş, SerdarSurgical treatment of primary tumor is a controversial treatment of stage IV de novo metastatic breast cancer (BC). This study aims to present early results of the ongoing reg istry in a cohort of patients.Article Citation - WoS: 69Citation - Scopus: 89Pectinase Enzyme-Complex Production by Aspergillus Spp. in Solid-State Fermentation: a Comparative Study(Elsevier, 2012) Heerd, Doreen; Yeğin, Sırma; Tarı, Canan; Fernandez Lahore, MarceloA comparative evaluation of three Aspergillus species according to their pectinase production in solid-state fermentation was performed. Solid-state fermentation offers several potential advantages for enzyme production by fungal strains. Utilization of agricultural by-products as low-cost substrates for microbial enzyme production resulted in an economical and promising process. The pectinolytic enzyme activities of two Aspergillus sojae strains were compared to a known producer, Aspergillus niger IMI 91881, and to A. sojae ATCC 20235, which was re-classified as Aspergillus oryzae. Evaluation of polymethylgalacturonase and polygalacturonase activity was performed as well as exo- vs. endo-enzyme activity in the crude pectinase enzyme-complex of the mentioned strains. Furthermore, a plate diffusion assay was applied to determine the presence and action of proteases in the crude extracts. A. sojae ATCC 20235 with highest polymethylgalacturonase activity and highest polygalacturonase activity both exo- and endo-enzyme activity, is a promising candidate for industrial pectinase production, a group of enzymes with high commercial value, in solid-state fermentation processes. Beside the enzymatic assays a protein profile of each strain is given by SDS-PAGE electrophoresis and in addition species-specific zymograms for pectinolytic enzymes were observed, revealing the differences in protein pattern of the A. sojae strains to the re-classified A. oryzae. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.Conference Object Bioethanol Production From Low Cost Agro-Industrial Waste Products(Elsevier, 2012) Evcan, Ezgi; Tarı, Canan; Özen, BanuIn recent years, the rapid increase in environmental problems, greenhouse gas emissions, fuel prices and the unlimited consumption of limited fossil fuel stocks made people search for some alternative energy sources. Bioethanol is one of the most popular alternative source with its many beneficial features. Besides, bioethanol which will be obtained from low cost raw materials will be more attractive. Bioethanol produced from lignocellulosic biomass sources, such as agricultural residues, offers unique environmental and economic benefits.Book Part Citation - Scopus: 4Bacteria: Arcobacter(Elsevier, 2014) Atabay, Halil İbrahim; Corry, Janet E.L.; Ceylan, ÇağatayThe genus Arcobacter currently comprises many phenotypically different species isolated from diverse niches. Although some Arcobacter spp. (particularly, Arcobacter butzleri, Arcobacter skirrowii, and Arcobacter cryaerophilus) are associated with various diseases in humans and animals, their exact epidemiological and pathological role is not completely understood, and few cases of human infection are reported. The primary mode of Arcobacter transmission is thought to occur via contaminated water and food and contact with pets. As some species are difficult to cultivate and all are difficult to identify using conventional biochemical tests, nucleic acid-based techniques such as polymerase chain reaction (PCR) and real-time PCR are increasingly used for their simultaneous detection, identification, and quantification. Their tendency to be resistant to antibiotics, and their ability to colonize food processing environments indicate that they could cause serious disease in the human population, particularly in susceptible individuals with impaired immune response. © 2014 Elsevier Inc. All rights reserved.Article Citation - WoS: 64Citation - Scopus: 77Development of Flexible Antimicrobial Zein Coatings With Essential Oils for the Inhibition of Critical Pathogens on the Surface of Whole Fruits: Test of Coatings on Inoculated Melons(Elsevier, 2019) Boyacı, Derya; Iorio, Gianmarco; Sözbilen, Gözde Seval; Alkan, Derya; Trabattoni, Silvia; Pucillo, Flavia; Yemenicioğlu, AhmetThis study aimed to develop essential oil (EO)-containing antimicrobial coatings for the inhibition of pathogenic bacteria contamination on fruit peels. Incorporation of eugenol (EUG), carvacrol (CAR), and thymol (THY) into films at > 1% (w/w) eliminated the typical brittleness of zein films. However, EUG outperformed CAR and THY in terms of mechanical properties. Films with >= 2% (w/w) CAR and THY and >= 3% EUG showed clear zones against L. innocua and E. coli in agar medium at 37 degrees C. All EO-containing films also inhibited L. innocua and E. coli inoculated at their surfaces by minimum 3.9 and 2.7 decimal (D) within 1 day at 10 degrees C. Moreover, 2% EUG-containing zein coatings caused 2-3 decimal reduction in L. innocua and E. coli counts of inoculated melon surfaces at 10 degrees C. Unlike the bare zein coatings, flexible EUG-containing films on melons did not show cracking or detachment. Zein films loaded with EUG showed a highly hydrophilic surface. The best oxygen barrier performance was observed for the EUG-richest formulation (i.e., EUG at 3%), and this was attributed to a homogenizing effect of the EO that eventually led to a denser and hole-free network. This work suggested that flexible coatings of zein containing EOs could inhibit pathogens embedded in the rough peel surface of melons.Article Citation - WoS: 61Citation - Scopus: 70Use of Ftir and Uv-Visible Spectroscopy in Determination of Chemical Characteristics of Olive Oils(Elsevier, 2019) Uncu, Oğuz; Özen, Banu; Tokatlı, FigenIt was aimed to predict fatty acid ethyl ester (FAEE), wax, diacylglycerol (DAG) and color pigment contents of olive oils by using rapid and non-destructive spectroscopic techniques (FTIR and UV-vis) individually and in combination. Prediction models were constructed by using partial least squares (PLS) regression with cross and external validation. FAEEs were estimated best with FTIR + UV-Vis spectroscopy (R-cv.(2) = 0.84, R-pred(2) = 0.90, and RPD = 3.0). PLS model with R-cv.(2) = 0.79, R-pred(2) = 0.71, and RPD = 1.9 was obtained for the estimation of 1,2 DAG using FTIR spectral data. Major pigments, lutein, pheophytin a and their derivatives and total xanthophylls were quantified successfully by FTIR + UV-Vis with a range of R-cv.(2) of 0.71-0.85, R-pred(2) of 0.70-0.84, and RPD = 1.5-2.5 values but the prediction of the rest of the pigments were poor (R-cv(2) = 0.60-0.76, R-pred(2) = 0.42-0.62, and RPD = 1.2-1.5). Combination of two spectral data resulted in average prediction of wax content of oils (R-cal(2) = 0.95, R-pred(2) = 0.75, and RPD = 1.9). FTIR and UV-vis spectroscopic techniques in combination with PLS regression provided promising results for the prediction of several chemical parameters of olive oils; therefore, they could be alternatives to traditional analysis methods.Article Citation - WoS: 52Citation - Scopus: 69Identification of Equivalent Processing Conditions for Pasteurization of Strawberry Juice by High Pressure, Ultrasound, and Pulsed Electric Fields Processing(Elsevier, 2019) Yıldız, Semanur; Pokhrel, Prashant Raj; Ünlütürk, Sevcan; Barbosa-Canovas, Gustavo, VThe objective of this study was to evaluate the effectiveness of high pressure processing (HPP), ultrasound (US) and pulsed electric fields (PEF) for the pasteurization of strawberry juice (SJ). Acid-adapted Escherichia coli was used to inoculate SJ prior to treatment with HPP, US, and PEF. HPP was applied at several pressures (200-400 MPa) up to 2 min while US (120 mu m, 24 kHz) was conducted at 25, 40, and 55 degrees C up to 10 min in continuous pulsing mode. In order to avoid excessive use of SJ, PEF was performed using a model solution (MS) basically composed of citric acid (8 g/L), fructose (35 g/L), glucose (35 g/L), Na2HPO4 (0.2 M) and NaCl (5%) to simulate the SJ electrical conductivity, pH, and total soluble solid (TSS). A face-centered composite design was conducted for PEF processing at different electric field intensities (EFI) (25-35 kV/cm) and treatment times (5-27 mu s). Processing conditions were selected that resulted in 5-log CFU/mL inactivation of E. coli. HPP at 300 MPa for 1 min, and US at 55 degrees C (thermosonication) for 3 min reduced E. coli in SJ by 5.75 +/- 0.52 and 5.69 +/- 0.61 log CFU/mL, respectively. PEF treatment at 35 kV/cm, 27 mu s treatment time, 350 mL/min flow rate, and 2 mu s pulse width in monopolar mode resulted in 5.53 +/- 0.00 log reduction of E. coli in MS. Likewise, E. coli population in SJ was also reduced by 5.16 +/- 0.15 log after applying the same PEF conditions to SJ. No E. coli was detected in SJ subjected to conventional thermal pasteurization at 72 degrees C for 15 s. All technologies reduced the natural microbiota below 2 log CFU/mL in terms of the total aerobic bacteria and yeast-mold counts. Thus, this study identified the equivalent conditions for the SJ pasteurization by three nonthermal processing technologies. Industrial relevance: Consumers have an increasing interest towards fresh-like food products with desirable nutritional and sensorial attributes. High pressure, ultrasound and pulsed electric field are three relevant novel nonthermal technologies as alternatives to conventional thermal treatments. This study identified the processing conditions of these three nonthermal technologies for the pasteurization of strawberry juice based on equivalent inactivation of acid-adapted E. coli. From an industrial point of view, the established processing conditions are useful references for the development of novel berry juices. In addition to microbiological safety, this study on equivalent processing allows direct efficacy and quality comparisons of a given juice pasteurized by the three nonthermal technologies under consideration.Book Part Citation - WoS: 3Citation - Scopus: 5Basic Strategies and Testing Methods To Develop Effective Edible Antimicrobial and Antioxidant Coating(Elsevier, 2018) Yemenicioğlu, AhmetDue to the continuous increase in microbial outbreaks originated form minimally processed and ready-to-use food [1,2], the active food packaging has become one of the top research topics in food science. A properly designed active packaging might increase the microbial safety or delay the spoilage of food (antimicrobial packaging), it might delay oxidative changes in food (antioxidant packaging), or it might help increasing functional properties of food by delivery of nutrients or bioactive substances to food surface in bioavailable form (bioactive packaging)Article Citation - WoS: 78Citation - Scopus: 83Rheological and Structural Characterization of Whey Protein Gelation Induced by Enzymatic Hydrolysis(Elsevier, 2016) Tarhan, Özgür; Spotti, Maria Julia; Schaffter, Sam; Corvalan, Carlos M.; Campanella, Osvaldo H.Whey proteins hydrolyzed by Bacillus licheniformis protease (BLP) form soft and turbid aggregate gels with potential food and biotechnological applications. The purpose of the study was to characterize protease-induced whey protein gelation by comparing different protein and enzyme concentrations in terms of gel mechanical and microstructural properties, and conformational changes in the protein secondary structure due to hydrolysis and gelation. Gels formed with whey protein isolate (WPI), at concentrations 5 and 10% (w/v), and BLP concentrations, BLP/WPI (w/w), of 1, 3, and 5% were studied. Regardless of the enzyme concentration, gels with 10% WPI were strong and elastic while those with 5% WPI were weak. Gelation time decreased as the enzyme concentration increased for both protein concentrations. Gel strengths values of 10% WPI samples were independent of BLP concentrations at the end of the incubation period. Creep tests performed on the resulting gels showed that 10% WPI gels with different BLP concentration had similar elasticity, slightly increasing with BLP amount. Remarkable differences were observed in the microstructures of gel prepared with different concentrations of protein and BLP. Changes in the protein secondary structure measured during the gelation were small before gelation. However, sudden changes were observed when the samples gelled, and also after 7 h of incubation at 50 degrees C (time in which samples reached a plateau in G* as seen by rheology tests). Results revealed that without enzyme, hydrolysis of the protein was not promoted and the protein secondary structure remains the same; only a slight denaturation was observed when the protein was incubated at 50 degrees C. (C) 2016 Elsevier Ltd. All rights reserved.Book Part Citation - Scopus: 21Short-Wave Ultraviolet Light Inactivation of Pathogens in Fruit Juices(Elsevier, 2018) Baysal, Ayşe HandanFruit juice processing techniques are continuously developing to conform to modern consumer demands for safe, nutritious, tasty, natural, and fresh-like products. Short-wave ultraviolet (UV-C) light has been proven to be a suitable alternative processing method because of its positive consumer image and low processing cost. The use of UV-C light at 253.7. nm for food processing is safe and has been approved as an alternative treatment to reduce pathogens and other microorganisms in the production, processing, and handling of foods. The bactericidal mechanism of UV-C is based on the absorption of UV-C light by microbial DNA or RNA structures and the formation of pyrimidine dimers, preventing replication, making pathogens inactive and unable to cause infection. Fruit juices have a range of optical and physical properties and diverse chemical compositions that influence UV-C efficacy. Thus, this chapter describes the effect of UV-C light applications on the inactivation of pathogens in fruit juice and critical factors to ensure efficient treatment. © 2018 Elsevier Inc. All rights reserved.