Sürdürülebilir Kalkınma Amaçları
Yayınlar
- Kitap BölümüAçık Erişim2024Recent trends in evaporation techniques
Icier, Filiz; Doner, Deniz; Cokgezme, Omer Faruk; Sabanci, Serdal; Cevik, Mutlu
Increasing energy costs of the food industry and the necessity to reduce emissions of greenhouse gases orient the researchers to find alternative solutions to increase energy efficiency, and to decrease waste and environmental damage. Hence, the use of novel technologies comes to the fore. Since volumetric heating could be provided by Ohmic and microwave heating methods, a heating medium is not required. Thus it is possible to reduce undesirable changes in quality attributes by eliminating contact with hot surfaces and providing rapid heating. The negative effects on the environment could also be reduced owing to both utilization of efficient energy for the heating process and the elimination of wastewater. Alternative nonthermal methods including ultrasound, membrane filtration, pulsed electric field, and electroplasmolysis techniques could also be applied. In this chapter, recent studies on the evaporation techniques, regarding their system setups, effects on the quality characteristics, and performance evaluations are reviewed.
- MakaleYalnız künye2022Scopus SJRQ1Evaluation of an ohmic assisted vacuum evaporation process for orange juice pulp
Sabanci, Serdal; Icier, Filiz
An ohmic assisted vacuum evaporation (OAVE) processes was used to concentrate orange juice from 11.4% total soluble solid content (TSSC) to 42% TSSC by applying 13 V/cm constant voltage gradient at different temperatures. The evaporation temperatures were adjusted to 100 °C, 85 °C, 75 °C and 65 °C by setting absolute system pressures of 101.32 kPa, 58 kPa, 39 kPa and 25 kPa, respectively. The total time for the processes, including heating and evaporation, was 34, 40, 48, and 54 min for 100, 85, 75, and 65 °C, respectively. As the evaporation temperature increased, the applied energy required for phase change decreased while maximum current values increased from 0.6 A at 65 °C to 2.52 A at 100 °C. During any given run, the current value increased as the orange juice pulp heated up, but then decreased after it began to boil, leading to a reduction in the rate of heat generation. Increasing evaporation temperature has a positive effect on evaporation rates, energy efficiency, specific water removal ratio (SWRR), exergy efficiency, and Improvement Potential (IP) (p < 0.05). The reduced energy requirement with higher temperature is partially due to reduced work from the vacuum pump at the higher absolute pressure.
AtıfScopus19WoS11OpenAlex16
İncele - MakaleAçık Erişim2021The Effect of Using Cow and Goat Milk on Antioxidant, Rheological andSensory Properties of Kefir
Icier, Filiz; Koca, Nurcan; Sabanci, Serdal; Çağındı, Özlem; Benzer Gürel, Duygu; Akyol, Merve Ildız
In recent years, demand for products produced with goat milk has been increasing. On the other hand, compared to cow's milk, component and flavour differences in goat milk can cause significant differences in the properties of products produced with goat's milk and affect the acceptability of the product. In this study, it was aimed to compare the antioxidant capacity, rheological and sensory properties of kefir produced with goat milk with those properties of kefir produced of cow milk. In this context, cow milk, goat milk and 1: 1 ratio of cow and goat milk kefir were produced, physico-chemical, rheological and sensory analyses were performed. It was determined that the rheological properties of all kefir samples exhibit pseudoplastic behaviour and are compatible with the power-law model. The apparent viscosity of the kefir produced by the goat milk was lower than cow milk kefir. It was determined that the total antioxidant capacity of goat milk kefir was higher than cow's milk kefir and a and b values were lower in colour. On the other hand, in goat milk kefir, panellists perceived lower consistency and kefir flavour, also its overall acceptability score was lower. The addition of 50% cow's milk to goat's milk influenced the condition of goat's milk. The sensory properties of the mixture milk kefir were similar to the sensory properties of the cow's milk kefir. Although the mixture kefir positive results, it has been concluded that further studies are needed to obtain better consistency and flavour in kefir production from goat milk.
AtıfOpenAlex5TR Dizin1
İncele - MakaleYalnız künye2021Scopus SJRQ2Infrared drying of dill leaves: Drying characteristics, temperature distributions, performance analyses and colour changes
Tezcan, Derya; Sabancı, Serdal; Cevik, Mutlu; Cokgezme, Omer Faruk; Icier, Filiz
Thin-layer drying behaviour of dill leaves samples under three different infrared radiation power intensities was investigated. Diffusion Approach was found to be the best model that describes the drying behaviour of dill leaves. Effective diffusivity values were 6.97 × 10−9, 6.84 × 10−9 and 8.96 × 10−9 m2/s for power intensities of 1790, 1970 and 2070 W/m2, respectively. According to the first and second law efficiencies, the infrared drying system was more efficient at higher power intensities (p < 0.05). However, the total colour change was maximum at the highest power intensity. For the investigated infrared drying conditions, 1970 W/m2 was recommended as the best-infrared power intensity applied for drying of dill leaves by taking into account both performance analyses and quality changes.
AtıfScopus40WoS34OpenAlex44
İncele - MakaleYalnız künye2021Scopus SJRQ1Numerical simulation of temperature histories of frozen minced meat having different fat contents during ohmic thawing
Cevik, Mutlu; Icier, Filiz
The ohmic thawing (OT) of minced meat sample was mathematically modelled using different numerical methods (Finite Difference-FD and Finite Volume-FV) for different process conditions (voltage gradients of 10, 13 and 16 V/cm and fat contents of meat sample as 2%, 10% and 18%). FD method was successful to predict the temperature changes for both heating and phase change regions. FV method was performed by using two different heat generation functions; depending on process time (UDF-1) or the center temperature (UDF-2). The description of the change of heat generation term depending on process time (UDF-1) in the ANSYS module was more successful with the experimental data compared to the description of the change of heat generation term depending the center temperature (UDF-2). Although FV model is more complex than FD model it can be applied for simulation of detailed temperature distributions. On the other hand, FD model can be applied for practical predictions of temperature histories for center temperatures in simple geometries. It is thought that the simulation of OT performed at different conditions with the FD and the FV methods would contribute valuable data in the design of household ohmic thawing/cooking systems for solid food materials.
AtıfScopus25WoS21OpenAlex21İncele - MakaleAçık Erişim2021Scopus SJRQ2Drying of licorice root by novel radiative methods
Icier, Filiz; Ozmen, Duygu; Cevik, Mutlu; Cokgezme, Omer Faruk
In this study, licorice root was successfully dried using two different radiative dryers (Carbon fiber-assisted cabin drying-CFACD and infrared drying-ID), and their effects on some drying characteristics, quality properties, and energy-exergy efficiency were investigated. Page and Verma models were the best models describing the drying behavior of licorice root for CFACD and ID methods, respectively. ID protected total phenolic content (TPC) better than CFACD while the changes of color properties were higher for ID. Energy and exergy efficiencies of CFACD were 40.20 ± 0.20% and 31.87 ± 0.10%, respectively, while these values were 10.39 ± 0.33% and 9.99 ± 0.27% for ID, respectively. Practical applications: The radiative heating method has advantages such as shorter drying time, high-energy efficiency, and high heat transfer coefficient compared to convective drying methods. Infrared drying (ID) is known as the common energy efficient drying method for food materials while the information on the performance of other type of radiative carbon fiber assisted drying (CFACD) systems is limited. In this study, the use of carbon fiber assisted cabin dryer for drying of licorice was evaluated by comparing other radiative type infrared dryer. The drying characteristics of licorice samples having high amount of phenolic contents were compared both in terms of quality and energy performance characteristics of dryers. Energy and exergy efficiencies of CFACD were found to be higher than ID. In addition, more homogeneous temperature distribution and less color change were obtained in the CFACD process. It was determined that the CFACD process could be recommended for drying of licorice samples rather than ID.
AtıfScopus18WoS13OpenAlex15İncele - MakaleAçık Erişim2021Scopus SJRQ2Comparison of quality attributes of minced beef samples thawed by ohmic and conventional methods
Cevik, Mutlu; Icier, Filiz
Frozen minced meat samples having different fat contents (2%, 10%, or 18%) were thawed using two different standard thawing methods (RT: +4°C refrigeration thawing, URWT: +4°C under running water thawing), and a novel alternative method (ohmic thawing-OT at voltage gradients of 10, 13, and 16 V/cm). The drip loss values of meat samples changed in the range of 0.01%–1.65%. For OT, the change in the color increased as the fat content increased. OT shortened the thawing time, on average, by 64% and 87% compared to URWT and RT, respectively, while it resulted in similar effects on proximate composition and microbiological load with standard thawing methods. This novel thawing method did not cause any mutagenic formation, and the metal migration was in allowable limits. It is thought that the results showed that OT method has the potential to be applied as a novel alternative method for thawing of meat products. Practical applications: For long-term storage of meat and meat products, freezing is commonly used. However, frozen food must be thawed before use. For this reason, two different conventional thawing methods were recommended by US-FDA. However, conventional thawing methods have some disadvantages such as long process times, high energy consumptions, and waste water formation. Ohmic thawing has shorter process time, high energy efficiency, and does not produce any waste water. In this study, frozen minced meat samples (with fat content of 2%, 10%, or 18%) were thawed using different thawing conditions (RT, URWT, and OT at voltage gradients of 10, 13, and 16 V/cm). OT shortened the thawing time. Drip loss was found to be high for OT. The effect of OT on microbiological load and proximate composition was not different from conventional thawing. OT method did not cause any mutagenic formation.
AtıfScopus26WoS23OpenAlex27İncele - MakaleAçık Erişim2020Ohmik destekli vakum altında evaporasyon sistemi ilekonsantre edilen nar suyunun reolojik özelliklerindekideğişimin incelenmesi
Icier, Filiz; Çokgezme, Ömer Faruk; Sabanci, Serdal; Çevik, Mutlu
Bu çalışmada, nar suyunun ohmik destekli vakum altında evaporasyon (OAVE) yöntemi ile farklı voltaj gradyanları (7.5, 10 ve 12.5 V/cm) uygulanarak %40 suda çözünür kuru madde (SÇKM) içeriğine kadar konsantre edilmesi sırasında reolojik özelliklerindeki değişim incelenmiş ve vakum altında evaporasyon (VAE) yöntemi ile karşılaştırılmıştır. Evaporasyon işlemi sırasında incelenen tüm SÇKM içeriklerinde nar suyu konsantrelerinin reolojik davranışını en iyi ifade eden modelin Üssel Model olduğu tespit edilmiştir. Bu model ile öngörülen görünür viskozite (µgörünür) ve akış davranış indeksleri (n) değerlerinin SÇKM içeriği arttıkça artma eğilimi gösterdiği belirlenmiştir. Yüksek voltaj gradyanlarında (10 ve 12.5 V/cm) uygulanan OAVE işlemi ile yüksek kıvam katsayısına sahip nar suyu konsantrelerinin elde edilebileceği tespit edilmiştir. Ek olarak, VAE işlemine benzer karakterde kıvama sahip konsantre eldesi için ise düşük voltaj gradyanında uygulanan OAVE işleminin alternatif olarak uygulanabilir olacağı sonucuna ulaşılmıştır.
AtıfOpenAlex3TR Dizin2İncele - MakaleYalnız künye2020Scopus SJRQ1ENHANCEMENT OF THE PERFORMANCE OF SOUR CHERRY JUICE CONCENTRATION PROCESS IN VACUUM EVAPORATOR BY ASSISTING OHMIC HEATING SOURCE
Sabanci, Serdal; Icier, Filiz
Sour cherry juice was concentrated to 65% TSS content by using ohmic heating assisted vacuum evaporation (OVE) at voltage gradients (10, 12, 14 V/cm) and vacuum evaporation (VE). The change of performance efficiencies (energy/exergy) of OVE process depending on the voltage gradient applied and the increase in TSS content during the process were investigated by taking into account of both process and system boundaries, and compared with those of VE process. During this process, total energy consumption decreased as the voltage gradient increased, but it increased as TSS content increased. System boundary based efficiencies were lower than process based ones. Maximum efficiency was obtained for 14 V/cm. Improvement potential values increased as TSS content increased but the voltage gradient increased. The assistance of ohmic heating to VE increased the performance of the evaporation process in terms of energy and exergy efficiencies, and decreased the improvement requirements of the system.
AtıfScopus31WoS24OpenAlex31İncele - MakaleYalnız künye2020Scopus SJRQ2Characterization of viscoelastic properties of minced beef meat thawed by ohmic and conventional methods
Cevik, Mutlu; Icier, Filiz
Frozen minced meat samples having fat contents of 2%, 10% and 18% were thawed using different methods (refrigeration thawing at ambient temperature of +4 ℃, under running cold water (+4 ℃) thawing, ohmic thawing for 10, 13 and 16 V/cm). Viscoelastic properties were determined by using rheological tests (oscillation and creep/recovery tests). Storage modulus, loss modulus, complex modulus, loss tangent, dynamic viscosity and complex viscosity values of minced meat samples increased as fat content increased. As frequency value increased, the modulus values of meat samples increased but dynamic and complex viscosity values of the samples decreased. The minced meat samples thawed by different methods had recoverable compliance values. The compliance values of meat samples during creep region can be well characterized by Burgers model. Ohmic thawing can be used as an alternative thawing method since it resulted in similar rheological properties of minced meat samples compared to refrigeration thawing at ambient temperature of +4 ℃ and under running cold water (+4℃) thawing.
AtıfScopus28WoS25İncele - MakaleAçık Erişim2020Scopus SJRQ2Rheological behavior of sour cherry juices concentrated by ohmic and conventional evaporation processes under vacuum
Sabanci, Serdal; Icier, Filiz
In this study, sour cherry juice was evaporated up to 65% total soluble solid content (TSSC) under vacuum (25 kPa) by ohmic-assisted vacuum evaporation (OAVE) and vacuum evaporation (VE). The effects of voltage gradients (10–14 V/cm) on the rheological behavior of sour cherry concentrates having different TSCC (30%–65%) were determined, and compared with those of VE. In general, the shear stress increased as the shear rate increased for all concentrations. Since the statistical error values of Power Law and Newton models were similar (p >.05), the most appropriate model describing the rheological behavior was chosen as Newton model being more nominative and mathematically simpler. The viscosity of concentrates (30%–65%) varied in the range of 0.003–0.119 Pa.s. The increase in the viscosity values depending on TSSC during evaporation was similar for both processes. Thus, OAVE could be beneficial alternative method to VE for the purpose of producing fruit juice concentrates having similar rheological properties. Practical applications: It is an alternative evaporation method in the literature in recent years by integrating ohmic heating into the evaporation process. However, in order for the ohmic evaporation process to be an alternative, it is necessary to provide qualities of fruit juices similar to or better than the vacuum evaporation process. One of the most important features for the transportation of fruit juices in industrial transport lines is rheological properties. In this study, it is important to determine that the consistency of the product resulting from the use of ohmic heating support in evaporation does not differ from the conventional method. The data obtained in this publication will constitute an important data infrastructure for scaling OAVE operation to industrial systems as an alternative.
AtıfScopus10WoS6OpenAlex8İncele - MakaleYalnız künye2019Scopus SJRQ1Quality characteristics of pomegranate juice concentrates produced by ohmic heating assisted vacuum evaporation
Sabanci, Serdal; Cevik, Mutlu; Cokgezme, Omer F.; Yildiz, Hasan; Icier, Filiz
AtıfOpenAlex48İncele - MakaleYalnız künye2019Scopus SJRQ2Effects of Vacuum Ohmic Evaporation on Some Quality Properties of Sour Cherry Juice Concentrates
Sabancı, Serdal; Icier, Filiz
Sour cherry juice (SJ) having total soluble solid (TSS) content of 19.2 % was concentrated to 65 % TSS by applying vacuum ohmic evaporation (VOE) and vacuum evaporation (VE) methods under constant absolute pressure (25 kPa). Total monomeric anthocyanin content (TMAC) of sour cherry concentrate (65 % TSS) was found in the range of 1561.67–1777.38 mg/L whereas total phenolic content (TPC) varied in the range of 9,071.22–78,347.53 mg/L concentrate. TPC and TMAC values of juice concentrates were affected less from VOE process compared to VE (p < 0.05) while there was no significant difference between the total antioxidant activities of SJ concentrates obtained by both methods (p > 0.05). TMAC and TPC values increased as the voltage gradient applied increased (p < 0.05). VOE process preserved the color properties of juice concentrates better compared to the VE process. It was concluded that VOE method could be an alternative fast evaporation method to obtain high-quality fruit juice concentrates.
AtıfScopus35WoS31OpenAlex34İncele - MakaleYalnız künye2018Scopus SJRQ2Effects of voltage gradient and fat content on changes of electrical conductivity of frozen minced beef meat during ohmic thawing
Cevik, Mutlu; Icier, Filiz
Frozen minced beef meat samples having different fat contents of 2, 10, and 18% were thawed until their center temperature reached −1 °C in the ohmic thawing system. Ohmic thawing was conducted by applying different voltage gradients (10, 13, and 16 V/cm) at ambient temperature of 4 ± 0.5 °C. Effective electrical conductivity (EEC) values of the samples at −1 °C were 0.5774 ± 0.0558, 0.4231 ± 0.0510, and 0.3933 ± 0.0693 S/m for 2, 10, and 18% fat contents, respectively. The change of effective electrical conductivity with temperature was linear for temperature range of −18 °C/−9.5 °C while it was exponential for temperature range of −9.5 °C/−4 °C. Above −4 °C, the polynomial model was best model describing the change of EEC with temperature. Ohmic thawing process could be applied as an alternative novel technology for thawing of meat and meat products. It is thought that the results of present study would contribute valuable information to open literature. Practical applications: Researchers have given attention on investigation of alternative thawing methods for foods in recent years. Ohmic thawing has high energy efficiency, causes low drip loss and does not produce any waste water. Since it is controlled by heat generation caused due to passing of alternative current through food, the information on change of its electrical conductivity is crucial. The minced beef sample has heterogeneous structure such as muscle, connective, and adipose tissues. Thus, its effective electrical conductivity (EEC) varies depending on its composition. In this study, the relations between temperature and EEC of minced beef samples having different fat contents were determined for four different temperature ranges existed during ohmic thawing at different voltage gradients. EEC was very low at temperatures below −4 °C, and then it sharply increased above this temperature. Results of present study would give valuable information to food industry for setting up industrial scale ohmic thawing systems for meat and meat products.
AtıfScopus52WoS47İncele - MakaleYalnız künye2017Scopus SJRQ1Performance analyses for evaporation of pomegranate juice in ohmic heating assisted vacuum system
Cokgezme, Omer Faruk; Sabanci, Serdal; Cevik, Mutlu; Yildiz, Hasan; Icier, Filiz
AtıfOpenAlex83İncele - MakaleYalnız künye2017Scopus SJRQ1Applicability of ohmic heating assisted vacuum evaporation for concentration of sour cherry juice
Sabanci, Serdal; Icier, Filiz
Sour cherry juice having total soluble solids (TSS) of 19.2% was evaporated up to 65% TSS at vacuum (gauge pressure of 580 mm-Hg) by applying ohmic heating at three different voltage gradients (10–14 V/cm). Total process times were determined as 40, 55, 75, and 85 min for 14 V/cm, 12 V/cm, and 10 V/cm, and vacuum evaporation (VE), respectively. The change of moisture content during ohmic assisted vacuum evaporation and VE processes were investigated by seven different empirical models. The best fitting model was Midilli model for three different voltage gradients and VE. The electrical conductivity values at different voltage gradients varied between 0.41 and 1.13 S/m for different TSS contents. The changes of EC values were examined in detail for three different regions; heating up period, first evaporation period, and second evaporation period. EC increased until a critical % TSS content (32% TSS), then remained constant for certain time (until 45% TSS) depending on voltage gradient, and then it had tendency to decrease. Ohmic heat generation increased sharply during heating period, then decreased dramatically during evaporation periods. It is recommended that ohmic heating could be alternatively used as the heat source to shorten the process times of vacuum evaporation applied for concentration of fruit juices.
AtıfScopus91WoS77OpenAlex93İncele - MakaleYalnız künye2017Scopus SJRQ1Ohmic heating assisted vacuum evaporation of pomegranate juice: Electrical conductivity changes
Icier, Filiz; Yildiz, Hasan; Sabanci, Serdal; Cevik, Mutlu; Cokgezme, Omer Faruk
A novel electrical heating method, named as ohmic heating, was successfully integrated to vacuum evaporation system, and pomegranate juice was concentrated until its total soluble dry matter content reached to 40% by applying three different voltage gradients (7.5, 10, and 12.5 V/cm) at 180 mm Hg absolute pressure in this system. Total evaporation times were determined as 152, 78, and 53 min at the voltage gradients of 7.5, 10, and 12.5 V/cm, respectively. The concentration time of pomegranate juice was shortened about 56% by ohmic heating relative to conventional evaporation. The electrical conductivity values were increased up to reach 25% TSDM for 7.5 V/cm and at 35% TSDM for 10 V/cm, then showed a decreasing pattern. However, it was constant (0.55 ± 0.01 S/m) during evaporation process at 12.5 V/cm. It is recommended that the ohmic heating method could be successfully integrated to vacuum evaporation process to shorten the processing time significantly. Industrial relevance Ohmic heating has been utilized as alternative method for the purpose of heating, pasteurization, cooking etc., and relatively better products can be obtained by ohmic heating. Nowadays, energy efficient systems are needed in concentrated juice production. The integration of ohmic heating to the conventional vacuum systems could serve the production high quality juice concentrates with efficient use of energy. In present study, ohmic heating assisted vacuum evaporation of pomegranate juice was conducted, successfully. This method decreased the total process time for juice concentration, which is critically important for industrial scale productions. This novel method can be implemented to the fruit juice production lines by taking into account of design characteristics of ohmic systems such as electrical conductivity changes depending on both temperature and total soluble solids concentration. The effects of main process parameter, named as voltage gradient, on electrical conductivity changes during electrical heating assisted evaporation process has been also reported in the present study.
AtıfScopus93OpenAlex97İncele