Browsing by Author "Erim Kose, Yagmur"

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Degradation Kinetic Modeling of Bioactive Compounds and Enzyme Activity in Wheat Germ During Stabilization
(Elsevier, 2022) Erim Kose, Yagmur
The stability of alpha-tocopherol (alpha-toco), total phenolic content (TPC), antioxidant capacity (DPPH and ABTS center dot+ radical scavenging capacity assays), activity of lipase (LA) and lipoxygenase (LOX) were investigated during stabilization of raw wheat germ with an industrial convection oven at different temperatures (120, 130, 140, 150 and 160 degrees C) and times (0, 5, 10, 15, and 20 min). Degradation kinetics were best fitted by first-order reaction models for all measured parameters with high R2 and low root mean square (RMSE) values, except ABTSassay which was modeled accurately with the second-order model. The temperature dependence of rate constants for all degradation kinetic parameters were calculated according to the Arrhenius, Eyring-Polanyi, and Ball models. Following the Arrhenius and Eyring models, activation energy (Ea) ranged from 20.69 to 55.04 kJ mol- 1, activation enthalpy (Delta H*) ranged from 20.44 to 51.61 kJ mol-1 whereas the activation entropy (Delta S*) varied between -179.313 and -213.447 J mol-1K-1 for the stabilized germ, respectively. It can be concluded that heat treatment at 120 degrees C for 20 min was the best processing conditions to stabilize the raw germ to preserve its valuable bioactive compounds, antioxidant activity and the models can be useful to design different heat treatment conditions.
Determination of Simultaneous Heat and Mass Transfer Parameters of Tulumba Dessert During Deep-Fat Frying
(Wiley, 2017) Erim Kose, Yagmur; Dogan, Ismail Sait
The heat transfer ( h) of "Tulumba" dough was investigated depending on the water loss during frying at 150-180C. The plots of dimensionless temperature and concentration ratios against time were used to determine heat and mass transfer parameters. The mechanism of moisture transfer was studied. Effective mass transfer coefficient increased linearly, whereas effective moisture diffusivity increased exponentially with rising frying temperature. Moisture diffusivity were 1.77, 2.15, 2.69 and 3.59 x 10(-7) m(2)/s, and mass transfer coefficient were 3.009, 3.225, 3.445 and 3.695 x 10(-6) m/s for 150, 160, 170 and 180C, respectively. An Arrhenius type of relationship was found between temperature and the effective moisture diffusivity, so activation energy was calculated at 36.58 kJ/mol. On the other hand, higher oil temperature decreased the effective heat transfer coefficient during deep-fat frying. The maximum value was determined 182.41 W/m(2) C at 150C and the minimal value as 125.715 W/m(2) C at 180C.
Kinetic Modeling of Macroelement Concentration of Malatya Cheese Produced by Traditional Method
(Wiley, 2021) Yasar, Dogan; Erim Kose, Yagmur; Kose, Senol
In this investigation, the concentration kinetics of macroelements (Na, Ca, P, Mg, and K) for Malatya cheese due to salting in different ways (dry salted and brined) and storing at different temperatures (7 and 20 degrees C) for 120 days, were studied. Changes in macroelement of Malatya cheese for modeling were determined using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) at different storage times (0, 30, 60, 90, and 120 days). The zero-order kinetic model with R-2 of 0.91-0.99 was determined to be the best model for Na, Ca, and P contents for brined and dry salted cheese samples. While Mg and K contents of the dry salted cheese fit the first-order kinetic model, the second-order model was applied to describe K content of the brined cheese samples. These models would be useful in designing the process for using different salting methods in traditional cheeses and related calculations for these samples. Practical applications The concentration kinetics of macroelements of Malatya cheese during ripening was obtained which could be used to determine the loss of macroelement. In addition, calculations of the reduction of the macroelements concentration depend on the different salting methods and storage temperatures, which led to reducing the economic losses and optimizing their storage management. Therefore, these models applied to cheese have been found to have a promising appearance in predicting quality changes in the dairy industry.
Protective Effect of Grape Seed Oil-Loaded Nanofibers: Limitation of Microbial Growth and Lipid Oxidation in Kashar Cheese and Fish Meat Samples
(Elsevier, 2021) Ceylan, Zafer; Kutlu, Nazan; Meral, Raciye; Ekin, Mehmet Mustafa; Erim Kose, Yagmur
Grape seed oil-loaded nanofibers (gsN) having 414.8 +/- 58.7 nm diameter were fabricated using the electrospinning technique. Scanning electron microscopy images, encapsulation efficiency (92.4%), and molecular characterization analysis (FTIR) proved successful production of electrospun gsN. Limitation in total mesophilic aerobic bacteria count (TMABc) of kashar and fish meat samples coated with grape seed oil-loaded nanofibers and then stored at cold storage conditions was found in the range of 1.40 and 1.53 log during the experimental period. Coating with gsN as compared to the control group samples for each sample delayed rapid total yeast and mold growth in kashar (28%) and fish meat samples (20%) (p < 0.05). TBA value of fish control samples was increased from 1.38 to 2.06 mg MDA/kg in fish control samples and 1.65 mg MDA/kg in fish meat coated with gsN. In addition to fish samples, at the end of the 20th day, while the initial TBA value was determined as 1.32 mg MDA/kg, it reached 2.45 in kashar control samples and 2.18 mg MDA/kg in kashar coated with gsN. In this respect, besides microbiological limitation, grape seed oil nanofiber coating was found to be highly effective against the rapid oxidation in fish and kashar samples stored at 4 +/- 1 degrees C (p < 0.05). The use of grape seed oil within nanoformulation effectively provided obtaining higher quality products having two different matrices in the food industry. Therefore, this nano methodology provided with the electrospinning technique could play a guiding role for different food products in the industry as well.
A Study on Mineral Content of Whey Obtained From Turkish Strained Yogurt
(Publ House Bulgarian Acad Sci, 2019) Kose, Senol; Erim Kose, Yagmur; Altun, Ibrahim
The macro (Ca, Mg, K, Na, P) and micro (Zn, Fe, Mn, Cu) mineral content of whey obtained from traditional and industrial yogurt during the strained yogurt production were determined by Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). In the production of strained yogurt, a traditional method has been used, i.e. straining with a special cloth bag. It was determined that the industrial yogurt whey exhibited higher mineral content in comparison to traditional yogurt whey except for Fe content. The average highest mineral content was determined to be 2039.21 mg/L in Ca element of industrial yogurt whey and the lowest was 0.21 mg/L in Mn element of traditional yogurt whey. These results suggest that whey as biological waste has high potential to be valuable mineral content for new products or an ideal alternative compound.
Wheat Germ Oil Nanoemulsion for Oil Stability of the Cooked Fish Fillets Stored at 4 °c
(Springer india, 2020) Ceylan, Zafer; Meral, Raciye; Erim Kose, Yagmur; Cavidoglu, Isa
Production of wheat germ oil nanoemulsions (WGO), having 114.7 nm average zeta size, 0.144 PD index, 14.76 mV zeta potential value, were successfully carried out. TBARS, FFA, PV, CD, and CT tests, lipid nutritional quality indexes (AI, HH, PI, TI, EPA/DHA, PUFA/SFA, and n3/n6), color measurements, and the changes in sensory quality were studied in cooked mackerel fillets stored at 4 degrees C for 11 days. WGO nanoemulsion has delayed the increase in TBARS, FFA, PV, CD, and CT values of cooked fish fillets by 36.1%, 20.5%, 32.2%, 37.7%, and 68.4%, respectively. The changes in lipid nutritional quality indexes, b* value and sensory quality of cooked fish fillets treated with WGO nanoemulsions were found to be more stable. The oil quality of the cooked fish fillets treated with WGO nanoemulsions was successfully protected because of WGO loaded nanoemulsions provided a larger contact area on the surface of the fish fillets.