Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(6)
- Yilmaz, Mustafa Tahsin(4)
- Toker, Omer Said(3)
- Gul, Osman(2)
- Karaman, Safa(2)
- Karasu, Salih(2)
- Muslu, Asli(2)
- Oruç, Şeref(2)
- Sagdic, Osman(2)
- Saricaoglu, Furkan Turker(2)
- Tatlisu, Nevruz Berna(2)
- Yılmaz, Bahadır(2)
- Arici, M.(1)
- Arici, Muhammet(1)
- Atalar, Ilyas(1)
- Bozkurt, Fatih(1)
- Cankurt, Hasan(1)
- Dertli, E.(1)
- Dikmetas, Dilara Nur(1)
- Durak, M. Zeki(1)
- Erten, Hüseyin(1)
- Genccelep, Huseyin(1)
- Karbancıoglu-Guler, Funda(1)
- Mortas, Mustafa(1)
- Oztekin, Sebahat(1)
- Sagdic, O.(1)
- Sancak, Kemal(1)
- Tatlisu, N.B.(1)
- Toker, O.S.(1)
- Toker, Omer S.(1)
- Tural, Serpil(1)
- Turhan, Sadettin(1)
- Yazici, Fehmi(1)
- Yilmaz, M.T.(1)
- Yilmaz, Mustafa T.(1)
- Yuzer, Mustafa Onur(1)
- Zehir Şentürk, Duygu(1)
- Şimşek, Ömer(1)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ2A novel exopolysaccharide from cold-adapted yeast Rhodotorula glutinis, along with structural, rheological, antioxidant, and antibiofilm properties
Oztekin, Sebahat; Dikmetas, Dilara Nur; Karbancıoglu-Guler, Funda
In the present study, a novel exopolysaccharide EPS-BMD26 produced by cold-adapted yeast Rhodotorula glutinis was structurally examined, along with its rheological, antioxidant, and antibiofilm properties. High-performance liquid chromatography (HPLC) analysis revealed glucose and galactose as two monosaccharide constituents. The functional groups within the EPS-BMD26 structure were detected by Fourier transform infrared (FT-IR) spectroscopy. The 1H and 13C nuclear magnetic resonance (NMR) spectra of EPS-BMD26 also confirmed its β-D-glucan type with galactose residues with an average molecular weight of 118 kDa. Differential scanning calorimetry (DSC) analysis revealed that EPS-BMD26 had a high level of thermal stability, up to 326.16 °C. Scanning electron microscopy (SEM) analysis demonstrated that EPS-BMD26 had a porous microstructure with fissures. X-ray diffraction (XRD) analysis revealed its semi-crystalline nature. EPS-BMD26 showed moderate and concentration-dependent antioxidant potential recruiting different methods, including •OH, DPPH•, CUPRAC, and ABTS radical scavenging activities. Water-soluble EPS-BMD26 exhibited high water holding capacity of 190 ± 0.22% with a water solubility index of 60.6 ± 8.3%. At 1.25 mg mL-1, EPS-BMD26 inhibited biofilm formation of Staphylococcus aureus ATCC 25923 by 79.5%. Rheological characterization revealed that the aqueous solution of EPS-BMD26 had shear thinning and pseudoplastic behavior. Given these properties, EPS-BMD26 may be a promising bio-hydrocolloid, antibiofilm agent, and food additive for industrial applications.
AtıfScopus15WoS15OpenAlex17
İncele - MakaleYalnız künye2024Scopus SJRQ2Effect of sesame protein/PVA nanofibers on oil separation and rheological properties in sesame paste
Yuzer, Mustafa Onur; Genccelep, Huseyin
This study aimed to prevent or minimize the oil phase separation that occurs during storage (0-90 days) of sesame paste at room temperature. In order to determine the changes during storage in the sesame paste samples, the zeta potential, rheological properties, and the separated oil ratio were determined. Significant (p < 0.01) effects of applied storage time and additives on the amount of oil separated in sesame pastes were determined. The oil separated in sesame paste samples varied between 3.83% and 16.29%. While the rate of separated oil increased three times in the control group over time, it showed an insignificant (p > 0.05) increase especially in the samples where 2% nanofiber was added. It was determined that the separation of the oil phase from the structure could be prevented up to 24.73% with the addition of SPI and up to 63.02% with addition of SPINL (nanofiber containing protein isolate) compared to the control. Practical applications: During storage, the particles in the sesame paste tend to precipitate, causing oil separation and residue cake, thus negatively affecting the acceptability of consumers. Additives were added in order to prevent or minimize oil phase separation, which occurs in sesame paste stored at room temperature and is not desired by consumers. As additives, nanofibers containing sesame proteins produced by the electrospinning method and sesame protein isolates (SPIs) were added. Added additives acted by preventing the separation of the oil phase from the structure. It has been determined that the addition of SPI to sesame pastes does not completely prevent the problem of oil separation in sesame paste, but is effective in delaying and reducing it. Since the oil decomposition can be reduced, the amount of oil separated and therefore the part that can sink to the bottom will decrease, so sesame paste will be consumed more appropriately and will contribute to the country's economy.
AtıfScopus9WoS7OpenAlex7İncele - MakaleAçık Erişim2020Scopus SJRQ2Structural and technological characterization of ropy exopolysaccharides produced by Lactobacillus plantarum strains isolated from Tarhana
Zehir Şentürk, Duygu; Dertli, Enes; Erten, Hüseyin; Şimşek, Ömer
Exopolysaccharide producing starter cultures enable manufacturing “clean labeled” foods with improved textural and nutritional properties. The structural and technological analyses were performed on the ropy exopolysaccharides of six Lactobacillus plantarum. The incubation temperature, time and pH affected the exopolysaccharide production and high exopolysaccharide was produced in the presence of sucrose and maltose. The viscosity of exopolysaccharide was high at acidic conditions except PFC311E that showed viscous at neutral pH. Lactobacillus plantarum strains produced between 120 and 400 mg/L exopolysaccharide in which the highest was observed at L. plantarum PFC311. Exoploysaccharides were degraded over 300 °C except PFC311E that degraded at 295.7 °C. The NMR analyses revealed that the exopolysaccharides were synthesized by α1-6, α1-3 and α1-4 bonds with glucose, galactose and fructose moieties. In conclusion, L. plantarum PFC311 produced ropy exopolysaccharide with different structural, rheological and thermal properties and reveals potential to be used in food industry.
AtıfScopus42WoS37OpenAlex36İncele - MakaleYalnız künye2017Optimization of Pectin Extraction from Orange Pulp and Characterization of Compositional and Steady Shear Properties
Yilmaz, Mustafa Tahsin; Muslu, Asli; Karasu, Salih; Bozkurt, Fatih; Dertli, Enes
Pectin, which is one of the most important wastes of fruit juice industry, was extracted from orange pulp at optimum conditions (pH, time and temperature) and modified using pectinase. The effect of modification on the structural properties of pectin was monitored using Fourier transformed infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) analyses. The bands at 1600-1800 cm(-1) which indicate the specific region and quality of pectin were detected using FTIR while galacturonic acid content was determined using HPLC. The results showed that the galacturonic acid content of pectin from orange pulp was determined to be 406.44 mg/g powder pectin while that of the modified pectin from the orange pulp was determined to be 465,34 mg/g powder pectin. In addition, flow properties of the pectin samples were determined using rheological analysis. The viscosity and viscoelastic properties of the modified pectin samples were revealed to be different from those of non-modified pectin samples. The consistency index values of unmodified and modified pectin samples were determined to be 0.0559 Pa.s(n) and 0.0046 Pa.s(n), respectively.
AtıfWoS3İncele - MakaleAçık Erişim2017Scopus SJRQ1Effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milk
Gul, Osman; Saricaoglu, Furkan Turker; Mortas, Mustafa; Atalar, Ilyas; Yazici, Fehmi
The effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milks was investigated. Hazelnut milk samples were produced from cold pressed hazelnut cake and homogenized up to 150 MPa pressure. Microstructural and rheological properties of products, except temperature sweep, were greatly affected by HPH treatments. Homogenized samples showed significant reduction in particle size, which turned from bimodal and poly-disperse to monodisperse distributions. HPH decreased the consistency of products from 91.82 to 0.51 Pa.sn and increased flow behavior index from 0.15 to 0.36. All samples showed higher values G′ than G″, which indicates that samples could be classified as soft-gel network, and hazelnut milk samples did not obey the Cox-Merz rule without multiplying angular frequency with shift factor. In conclusion, HPH can be used to reduce the consistency of samples and the friction loss, thus minimizing the amount of energy required to flow during processing and distribution. Industrial relevance. Vegetable based beverages are available at any supermarket as an alternative to dairy products with an increasing consumer acceptance. Between these beverages hazelnut milk samples are the most noteworthy products due to important role in human nutrition and health, and moreover due to well accepted and widely consumed product. Due to its composition, hazelnut milks have very high consistency, and therefore, the energy consumption for processing and handling is too high. In this research, the high pressure homogenization (HPH) technology was successfully proposed to be used for improving microstructural properties, and hence reducing its consistency. The energy consumption during processing and distribution can be minimized by reducing the consistency and friction losses of product.
AtıfScopus97WoS80OpenAlex100İncele - MakaleAçık Erişim2017Scopus SJRQ1Potential application of high pressure homogenization (HPH) for improving functional and rheological properties of mechanically deboned chicken meat (MDCM) proteins
Saricaoglu, Furkan Turker; Gul, Osman; Tural, Serpil; Turhan, Sadettin
The potential application of high pressure homogenization (HPH) for modifying the solubility, emulsifying and foaming properties, particle size distributions, zeta potential and rheological properties of mechanically deboned chicken meat (MDCM) proteins was evaluated. HPH decreased particle size, produced higher zeta potential and stronger electrostatic repulsion, and hence, improved water solubility, as well as emulsifying, foaming properties, flow ability and dynamic shear properties of protein suspensions. Steady and dynamic shear results indicated that samples had shear-thinning and soft-gel network behavior due to higher G′ than G″. Creep and recovery tests were explained with Burgers and exponential decay models, respectively, and led to a better understanding the internal structure, as well as elastic and viscous behavior. The final percentage recovery increased as homogenization pressure increased due to strengthened solid-like structure of protein suspensions. These results revealed that HPH can be a valuable process to improve functional and rheological properties of MDCM proteins.
AtıfScopus53WoS51OpenAlex56İncele - MakaleYalnız künye2016Rheological and Molecular Characterization of Modified Pectin from Sugar Beet Meal
Yilmaz, Mustafa Tahsin; Muslu, Asli; Dertli, Enes; Toker, Omer Said
The pectin was produced from sugar beet pulp, one of the significant waste of sugar industry, at optimum conditions (pH, time and temperature). Then, the modification was carried out using pectinase. FT-IR (Fourier transform infrared spectroscopy) and HPLC (high performance liquid chromatography) analysis were performed to characterize the differences between modified and unmodified pectin. FT -IR analysis revealed the specific regions of pectin and 1600-1800 cm-1 bands. Galacturonic acid content was analyzed by HPLC. The obtained results revealed that the modified pectin had higher galacturonic acid content. In addition, flow properties of the modified pectin was also determined. The flow characteristics of modified pectin was observed to change.
AtıfWoS1İncele - MakaleAçık Erişim2016Scopus SJRQ1Improvement in performance properties of asphalt using a novel boron-containing additive
Oruç, Şeref; Yılmaz, Bahadır
In current times, many additives are used to improve the performance characteristics of asphalt. In this study, a new additive that contains boron, given the short name of cyclic borate ester (CBE), was chemically synthesised in laboratory conditions. It was added to the asphalt binder as 1%, 2%, 4% and 6% ratios of asphalt by weight, and modified asphalt samples were produced. The effects of CBE on the conventional properties of asphalt binder (penetration, softening point, ductility, flash point, Fraass breaking point) were examined using a dynamic shear rheometer, rotational viscosity, a rolling thin film oven, a pressure aging vessel and bending beam rheometer test methods. Results showed that the use of CBE additive increased the hardness, softening point, viscosity, flash-point value and rutting resistance of asphalt binder and decreased temperature sensitivity. CBE also enhanced elastic responses (increased complex shear modulus and decreased phase angle), aging resistance and low-temperature cracking resistance and did not change the cohesion property.
AtıfScopus25WoS24OpenAlex28İncele - MakaleAçık Erişim2016Scopus SJRQ1Development of a fermented ice-cream as influenced by in situ exopolysaccharide production: Rheological, molecular, microstructural and sensory characterization
Dertli, Enes; Toker, Omer S.; Durak, M. Zeki; Yilmaz, Mustafa T.; Tatlisu, Nevruz Berna; Sagdic, Osman; Cankurt, Hasan
This study aimed to investigate the role of in situ exopolysaccharide (EPS) production by EPS+ Streptococcus thermophilus strains on physicochemical, rheological, molecular, microstructural and sensory properties of ice cream in order to develop a fermented and consequently functional ice-cream in which no stabilizers would be required in ice-cream production. For this purpose, the effect of EPS producing strains (control, strain 1, strain 2 and mixture) and fermentation conditions (fermentation temperature; 32, 37 and 42°C and time; 2, 3 and 4 h) on pH, S. thermophilus count, EPS amount, consistency coefficient (K), and apparent viscosity (η50) were investigated and optimized using single and multiple response optimization tools of response surface methodology. Optimization analyses indicated that functional ice-cream should be fermented with strain 1 or strain mixture at 40-42°C for 4 h in order to produce the most viscous ice-cream with maximum EPS content. Optimization analysis results also revealed that strain specific conditions appeared to be more effective factor on in situ EPS production amount, K and η50 parameters than did fermentation temperature and time. The rheological analysis of the ice-cream produced by EPS+ strains revealed its high viscous and pseudoplastic non-Newtonian fluid behavior, which demonstrates potential of S. thermophilus EPS as thickening and gelling agent in dairy industry. FTIR analysis proved that the EPS in ice-cream corresponded to a typical EPS, as revealed by the presence of carboxyl, hydroxyl and amide groups with additional α-glycosidic linkages. SEM studies demonstrated that it had a web-like compact microstructure with pores in ice-cream, revealing its application possibility in dairy products to improve their rheological properties.
AtıfScopus86WoS74OpenAlex98
İncele - MakaleAçık Erişim2016Scopus SJRQ1Effect of boron-containing additives on rheological properties of asphalt binder
Oruç, Şeref; Yılmaz, Bahadır; Sancak, Kemal
In this study, four novel boron-containing additives were synthesised chemically in the laboratory. The modification was performed by adding the additives, respectively, into asphalt at a certain amount by weight at the same temperature and mixing conditions. The modification mechanism and microstructure of the blends were characterised by Fourier transform infrared spectrometer and scanning electron microscopy. The variation in modified samples in comparison to base asphalt was investigated by performing the penetration, softening point, dynamic shear rheometer, amplitude–frequency–temperature sweeps and rotational viscosity tests. It was observed that the additives increased the softening point, rutting resistance, elastic properties and viscosity of asphalt. The additive synthesised with triazole borate ester octanol-sulphuric acid catalysts gave the most enhancements, relative to base asphalt.
AtıfScopus20WoS17OpenAlex22İncele - MakaleAçık Erişim2015Scopus SJRQ1Effect of in situ exopolysaccharide production on physicochemical, rheological, sensory, and microstructural properties of the yogurt drink ayran: An optimization study based on fermentation kinetics
Yilmaz, M.T.; Dertli, E.; Toker, O.S.; Tatlisu, N.B.; Sagdic, O.; Arici, M.
Exopolysaccharide (EPS)-producing starter cultures are preferred for the manufacture of fermented milk products to improve rheological and technological properties. However, no clear correlation exists between EPS production and the rheological and technological properties of fermented milk products such as the yogurt drink ayran. In this study, 4 different strain conditions (EPS- and EPS+ Streptococcus thermophilus strains) were tested as a function of incubation temperature (32, 37, or 42°C) and time (2, 3, or 4 h) to determine the effect of culture type and in situ EPS production on physicochemical, rheological, sensory, and microstructural properties of ayran. Furthermore, we assessed the effect of fermentation conditions on amounts of EPS production by different EPS-producing strains during ayran production. A multifactorial design of response surface methodology was used to model linear, interaction, and quadratic effects of these variables on steady shear rheological properties of ayran samples and in situ EPS production levels. The physicochemical and microbiological characteristics of ayran samples altered depending on incubation conditions and strain selection. Steady shear tests showed that ayran samples inoculated with EPS+ strains exhibited pseudoplastic flow behavior. Production of ayran with EPS- strain (control sample) resulted in the lowest apparent viscosity values (η50), whereas those produced with the combination of 2 EPS+ strains yielded ayran with notably increased η50 values. We concluded that incubation time was the variable with the greatest effect on η50, consistency coefficient (K), and flow behavior index (n) values. In situ EPS production was also affected by these conditions during ayran fermentation in which strain-specific metabolism conditions were found to be the most important factor for EPS production. In addition, these findings correlated the amount of in situ EPS produced with the rheological properties of ayran. Scanning electron microscopy images of the samples showed differences in structural features, revealing a prominent network strand structure in the ayran samples inoculated with the admixture of 2 EPS-producing strains incubated at 37°C for 3 h. These results provide useful information for large-scale production of ayran by the dairy industry.
AtıfScopus79WoS65OpenAlex92İncele - MakaleYalnız künye2015Scopus SJRQ1Thermal loop test to determine structural changes and thermal stability of creamed honey: Rheological characterization
Karasu, Salih; Toker, Omer Said; Yilmaz, Mustafa Tahsin; Karaman, Safa; Dertli, Enes
This study was the first attempt to understand if thermal stability of any food product during storage could be determined. In this respect, a novel method, namely, the thermal loop test was used to determine structural changes and thermal stability of creamed honey in this study. The novelty of this method was that thermal stability of a product is tested within a number of thermal cycles over a determined range of temperature. Creamed honey was characterized in terms of physicochemical, thermomechanical and rheological properties. It showed non-Newtonian thixotropic behavior at all temperature levels (10, 25 and 40 °C). Time-dependent flow behavior was successfully defined by Weltman and second order structural models. Hysteresis loop area depended on temperature and decreased with increase in temperature. Creamed honey had liquid-like structure, showing that it had more pronounced viscous nature than elastic nature (G″ > G′). Temperature sweep tests were conducted to determine temperature dependency of η50, G′ and G″ values using Arrhenius equation. These test results confirmed the thermal stability test results, revealing that thermal loop test can be an accurate method to determine thermal stability of similar food products, as a new information. Relative structural index value (Δ) increased with number of thermal loop, suggesting that creamed honey had low thermal stability and showed a great structural change by the thermal stress applied between 5 °C and 50 °C. These results suggest that crystallized honey be abstained from large temperature fluctuations to avoid from irreversible changes in rheological characters; thus, to maintain spreadability.
AtıfScopus45WoS43OpenAlex47İncele - MakaleAçık Erişim2014Scopus SJRQ1Steady, dynamic and creep rheological analysis as a novel approach to detect honey adulteration by fructose and saccharose syrups: Correlations with HPLC-RID results
Yilmaz, Mustafa Tahsin; Tatlisu, Nevruz Berna; Toker, Omer Said; Karaman, Safa; Dertli, Enes; Sagdic, Osman; Arici, Muhammet
In this study, natural honey was adulterated with the addition of adulterants, namely saccharose and fructose syrups at a ratio of 0%, 10%, 20%, 30%, 40% and 50% by weight. Steady, dynamic and creep tests were conducted, revealing that the changes in the flow, viscoelastic and creep behavior of natural honey were clear and remarkable. Syrup addition decreased viscosity (η), storage (G') and loss modulus (G″) values of the control honey samples. Deformation represented by the compliance (J(t)) values was more prominent in the adulterated honey samples. In addition, HPLC-RID analysis was conducted to determine major sugar composition of the adulterated samples. Pearson's correlation test indicated that there were significant (P<0.05; 0.01) correlations between sugar composition and rheology parameters, η (viscosity), K″, K* (intercepts for G″ and complex modulus (G*), respectively) and η0 (viscosity of Maxwell dashpot), suggesting that K', K″, K* and η0 could be prominent indicators for presence of saccharose or fructose syrups added in natural honey within the studied concentration levels. These results suggested that use of steady, dynamic and creep analysis would be a novel and potential approach to detect honey adulteration by fructose and saccharose syrups.
AtıfScopus81WoS72OpenAlex80İncele