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 künye2024Scopus SJRQ1Optimization of Pectin Extraction from Lemon Peel Powder by Ohmic Heating Using Full Factorial Design
Çilingir, Seda; Duran, Gülseven; Gökyildiz, Beritan; Goksu, Ali; Sabanci, Serdal; Cevik, Mutlu
Ohmic heating-assisted extraction has emerged as an effective method preferred in recent years. This extraction method is affected by experimental factors such as temperature, process time, and voltage gradient. The present study aimed to optimize the pectin extraction process from lemon peel powder samples by the ohmic heating-assisted extraction method. In this study, the effects of 3 different voltage gradients (7, 9, and 11 V/cm), 3 different solid to liquid ratios (1:20 g/mL, 1:40 g/mL, and 1:60 g/mL), and 3 different holding times (0, 60, and 120 min) and their interactions were investigated to determine the optimum extraction condition at constant temperature (80 °C) and pH = 1 sulfuric acid solution. The factors examined in the optimization procedure were pectin yield, power consumption, and energy efficiency. The optimum conditions were found to be 11 V/cm voltage gradient, 1:60 g/mL solid to liquid ratio, and 120-min holding time with a desirability value of 0.778. The results of this study could give important information about the design of industrial scale ohmic heating units, especially from different food wastes in industrial pectin production.
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İncele - MakaleYalnız künye2022Scopus SJRQ2Investigation of the changes in rheological properties and some quality characteristics of probiotic fermented almond milk with added different ratios of orange juice
Duran, Gülseven; Cevik, Mutlu
In this study, the changes in pH, titratable acidity, survival of Lactobacillus acidophilus, mold and yeast counts, rheological properties, and sensory evaluation of fermented almond milk samples with and without added 100% orange juice at three different ratios (10%, 20%, and 30%) were investigated. pH and titratable acidity values of fermented almond milk samples varied between 3.97–4.40 and 0.178%–0.478% at the end of the fermentation process, respectively. It was determined that the survival of L. acidophilus content of fermented samples varied between 7.58 and 7.95 log CFU/ml. The best suitable rheological model for the flow behavior of all fermented almond milk samples was the Power-Law model. Fermented almond milk samples with added 20% and 30% orange juice was more preferred by the panelists. It is thought that the results of this study could provide valuable information for equipment and pumping systems that can be installed on an industrial scale. Practical applications: In recent years, cereals (oats, rice, corn), legumes (soybean, cowpea, chickpea), oilseeds (sesame, sunflower, flaxseed), and hard-shelled fruits (almond, coconut, hazelnut, peanut, walnut) is widely used in the production of plant milk. In this study, the changes in some quality and rheological properties of fermented almond milk samples with added different ratios of orange juice were investigated. It was determined that all fermented almond milk samples had high probiotic content at the end of the fermentation stage. As a result of the sensory evaluation, it was determined that the acceptability of fermented almond milk with added 20% and 30% orange juice was very high compared to other samples.
AtıfScopus2WoS2OpenAlex2İncele - 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.
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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 - MakaleYalnız künye2021Scopus SJRQ2Electrical conductivity and performance evaluation of verjuice concentration process using ohmic heating method
Cevik, Mutlu
The verjuice sample (14.5 ± 0.2% total soluble solid [TSS] content) was concentrated (at 102 ± 2°C evaporation temperature) until reach 50% TSS content by applying ohmic heating at 13, 15, 17, and 19 V/cm voltage gradients. The total process times up to 50% TSS content were determined as 2,100, 1,500, 1,200, and 1,020 s for 13, 15, 17, and 19 V/cm, respectively. The electrical conductivity values increased until reach 32% TSS content and then showed a decrease until the final TSS content. The total energy consumption values increased as the voltage gradient decreased. The total power and specific water removal ratio (SWRR) values decreased as the voltage gradient decreased. The efficiency of ohmic heating assisted concentration process increased with the applied voltage gradient and it ranged from 71.27 to 75.22%. By evaluating the effects of ohmic heating conditions applied in the present study on total process time, total energy consumption, and process efficiency, 19 V/cm voltage gradients could be recommended to be optimum evaporation conditions of verjuice concentration in case of decreasing process time and higher energy efficiency. Practical applications: Fruit juices are generally concentrated to extend their shelf life. Therefore, for concentration purposes, various techniques, such as thermal evaporation, freezing methods, and membrane techniques, are applied in the fruit juice industry. This technique has some disadvantages, such as high energy requirements, the formation of undesirable compounds, high initial investment cost, and high failure rate to reach the desired total soluble solid content. The ohmic heating method, which is among the alternative heating methods, has advantages such as high energy efficiency, shorter processing time, higher product quality, and not causing wastewater. As a result of this study, it is thought that the verjuice samples were successfully concentrated up to 50% TSS content by using the ohmic heating method and this method can be used as an alternative method instead of the traditional method due to higher process efficiency and shorter process time.
AtıfScopus23WoS19OpenAlex26İncele - 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 - 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 - 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 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 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.
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