Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ1Effect of Ohmic Heating on the Quality and Nutrient Preservation of Plum Marmalade: A Comparison With Conventional Heating
Ekici, Seymanur; Omac, Basri; Sabanci, Serdal
In this study, plum marmalade was prepared using the ohmic heating method at three distinct voltage gradients (30, 35, and 40 V/cm). The quality properties of the marmalade prepared this way were contrasted with those prepared using the conventional heating method. Total phenolic content (TPC), antioxidant activity (AA), vitamin C content, total color change (ΔE), hydroxymethylfurfural (HMF), and the amount of time needed for the process, including heating and evaporation, were all measured as part of the study. According to the findings, ohmic heating—specifically, a voltage gradient of 40 V/cm—significantly reduced the heating time when compared to the traditional method, which raised the stability of vitamin C, AA, and phenolic compounds. When ohmic heating was used instead of conventional heating, the amounts of TPC, AA, and vitamin C increased by 19.50%, 33.90%, and 149.12%, respectively. In comparison to traditional heating under atmospheric conditions, the results also showed that ohmic heating increased the amounts of gallic acid (40.61%), catechin (40.98%), chlorogenic acid (25.05%), and rutin (24.67%). Furthermore, the results showed that ohmic heating reduced the amount of HMF (34.34%) and ΔE (2.27%) in comparison to conventional heating. TPC, AA, vitamin C, gallic acid, catechin, chlorogenic acid, and rutin were higher than conventional heating; nevertheless, HMF and ΔE were lower than conventional heating at the applied ohmic heating process. The results obtained indicate a strong potential for an ohmic heating system as a rapid heating method for preserving nutritional value.
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İncele - MakaleAçık Erişim2024Modeling changes in the quality attributes of couscous cooked with ohmic heating
Sabanci, Serdal; Işık, Erdem; Goksu, Ali; Omaç, Basrı
Kinetic studies on the quality alters of couscous are crucial to the suitable design of ohmic heating treatment. Hence, it was targeted to build mathematical models to forecast the changes in quality attributes of couscous cooked using ohmic heating (OH) in the present study. In addition, the average power and total energy for cooking couscous with OH at a voltage gradient of 17 V/cm were determined. Three dissimilar kinetic models—zero, first, and second—were fitted to the data. Our findings showed that, for the ohmic heating system, as cooking time increased, energy consumption increased while heating system efficacy declined. The best model to reflect the changes in color parameters was the second-order model, while the zero-order model best fit the experimental data observed for the cooking loss, moisture content, and weight increase (%). For all TPA parameters, however, neither model yielded the greatest fit.
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İncele - MakaleAçık Erişim2024Ohmik Evaporasyon İşlemiyle Elde Edilen Dut Pekmezinde Renk Değerlerinin İncelenmesi
Sabanci, Serdal; Ak, Ferit
Evaporasyon işlemi sıvı gıda ürünü içerisinde bulunan suyun fiziksel olarak uzaklaştırılmasıdır. Bu işlemde geleneksel ısıtma teknikleri sonucunda istenmeyen bileşen oluşumu, kalite kaybı ve aroma kayıpları meydana gelmektedir. Bu nedenle gelişen teknoloji ile geleneksel gıda işlemi uygulamalarının yerini alternatif teknikler almaktadır. Bu tekniklerin başında ohmik ısıtma işlemi gelmektedir. Ohmik ısıtma işlemi iki elektrot arasında alternatif akım geçirilerek ürünün ısınma prensibine dayanmaktadır. Bu çalışmanın ana amacı üç farklı voltaj gradyanı kullanılarak elde edilen dut pekmezinin renk değerlerinin incelenmesidir. Örnekler ohmik evaporasyon işlemi ile üç farklı voltaj gradyanında atmosferik koşullar altında %22,2 Suda Çözünür Kuru Madde (SÇKM) içeriğinden %68 SÇKM değerine kadar evaporasyon işlemine tabi tutulmuştur. Örneklere ait L*, a*, ve b* renk değerleri ölçülmüştür. Elde edilen L*, a*, ve b* değerlerinden beyazlık ve kahverengileşme gibi bazı renk indeksleri hesaplanmıştır. Beyazlık indeksi (Bİ) ve kahverengileşme indeksi (Kİ) incelendiğinde, en yüksek değerler geleneksel yöntemde elde edilirken en düşük değerler 15 V/cm voltaj gradyanında elde edilmiştir. Toplam renk değişim değerinin 3,73-8,97 arasında değiştiği, en düşük renk değişim değerinin geleneksel yöntemle elde edildiği ve bu değerin yükselen voltaj gradyanı ile arttığı belirlenmiştir. Sonuç olarak, dut pekmezi örnekleri renk değişimleri açısından incelendiğinde genel anlamda voltaj gradyanın artmasından olumsuz etkilendiği tespit edilmiştir. Bununla birlikte fiziksel kalite değerlerinin başında yer alan renk değerleri bakımından nispeten daha düşük voltajlı ohmik evaporasyon işleminin kullanılabileceği düşünülmektedir.
AtıfOpenAlex1İncele - 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.
AtıfScopus7WoS7OpenAlex5İncele - MakaleAçık Erişim2023Investigation of Pectin Production by Ohmic Heating Assisted Extraction Method Using Different Types of Acids from Lemon Peel Powder
Sabanci, Serdal; Çevik, Mutlu; Goksu, Ali
Depending on the developing technology, people's use of alternative heating methods is increasing. In the present study, a solution of lemon peel powder prepared with 3 different acids (sulphuric, hydrochloric, and nitric acid) was heated from 20 °C to 80 °C at a constant pH of 1.5, solid: liquid ratio (1:40), and a voltage gradient of 10 V/cm. It is aimed to investigate the change of electrical conductivity value and the effect of acid type on pectin yield at the end of 10 minutes of processing time at 80 °C extraction temperature. As a result of the experiments, the heating times of the samples in the ohmic heating-assisted extraction system varied between 199 and 252 s, and the electrical conductivity values varied between 0.89 and 2.10 S/m. In addition, the electrical conductivity value increased in 3 different acid types as the temperature value increased. Also, pectin yield values for 3 different acid types varied between 8.88% and 10.72%, and the highest pectin yield was obtained in the extraction process obtained from the solution prepared with sulfuric acid. It was determined that the use of different acid types had a significant effect on the heating time, electrical conductivity, and pectin yield (p0.05). According to the results, it has been determined that pectin extraction can be done successfully using the ohmic heating-assisted extraction system. It is expected that the data obtained from the use of current heating methods in the extraction of such products will make a serious contribution to the literature.
- MakaleAçık Erişim2023The effect of ohmic heating on the quality properties of couscous during cooking
Sabanci, Serdal; Işık, Erdem; Goksu, Ali; Omaç, Basrı
Couscous has been widely eaten around the world because it has a low glycemic index, is low in fat, and is simple to prepare. However, it should be cooked before consumption. Therefore, novel heating methods, such as ohmic heating, can be used to cook couscous. This study aimed to investigate the potential use of ohmic heating at a voltage gradient of 17 V/cm to cook couscous and compare it with the conventional cooking method. To determine the effect of ohmic heating and conventional methods on the quality properties (color, texture profile analysis, cooking loss, moisture content, and weight increase (%)) of couscous, samples were cooked in a 0.1% salt solution. The samples were analyzed at different cooking times (4, 8, 12, and 16 min). The results obtained in the present study revealed that the total color difference also increased with an increase in cooking time. In addition, similar trends were observed for cooking loss, moisture content, and weight gain. Furthermore, the couscous samples treated with ohmic heating and conventional heating methods were completely cooked after 12 minutes. Overall, compared to the conventional cooking method, the ohmic heating process did not induce any negative effects on the quality parameters of couscous.
AtıfOpenAlex1TR Dizin1İncele - MakaleAçık Erişim2023Application of the Ohmic Heating Process to Make a Semolina Dessert with Milk
Sabanci, Serdal; Omaç, Basrı; Yüksel, Hatice Pınar
Traditional milk desserts are one of the most essential dessert groups that Turkish society consumes. Due to foaming activity, it was aimed to investigate the feasibility of the ohmic heating system to produce a semolina dessert with milk. Hence, an ohmic heating treatment was used to heat the milk, semolina, and sugar mix from 20°C to 100°C using three different voltage gradients (15, 17.5, and 20 V/cm) and then boil for two minutes. It was found that the current value escalated from 20°C to approximately 86°C but decreased after 86°C due to foaming. Since the total consumed energy during the ohmic cooking treatment was inversely proportional to the treatment time, the total consumed energy values decreased based on the rising voltage gradient. As a result, the feasibility of the ohmic heating treatment for making a traditional semolina dessert with milk was determined in this study.
- MakaleAçık Erişim2023Scopus SJRQ2Modeling the electrical conductivity value of the model solution
Sabanci, Serdal; Kaya, Kübra; Göksu, Ali
The ohmic heating process is one of the novel electrical heating methods that are considered as fast, homogeneous and efficient heating. In this study, the details of the relationship between electrical conductivity (EC)-Temperature (Temp) and EC-pH-Temp at different Total Soluble Solid Content (TSSC) and different pH values were examined. Especially, the study explains details of the electrical conductivity value due to pH change (2, 2.5, 3, 3.5) and expressing EC change depending on the pH value of fruit and vegetable juices. At constant pH, EC values decrease with increasing TSSC values (10%, 20%, 30%, 40%, 50%, 60%) and decrease with increasing pH at constant TSSC value. When the relationship between Temp-EC is analyzed that the EC value increases as Temp increases in all cases and this increase is linear. It was found that the Temp-EC relationship was in high compatibility with an R2 value above 0.97. Also, in the Temp-EC-pH relationship, the R2 value was found to be an acceptable value above 0.95.
AtıfScopus4WoS3İncele - 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.
AtıfScopus19WoS11OpenAlex16İncele - MakaleYalnız künye2022Scopus SJRQ2Investigation of electrical conductivity and bioactive quality during ohmic evaporation process of Apple juice
Karakavuk, Emrah; Goksu, Ali; Sabanci, Serdal
In this study, the evaporation of apple juice was completed with ohmic heating to eliminate some problems with conventional evaporation methods. Ohmic evaporation (OE) was performed at different voltage gradients (13–17 V/cm) for determining electrical conductivity (EC), Hydroxymethylfurfural (HMF), and the total phenolic content (TPC) changes. The voltage gradient affected the total consumed energy, average power, and specific water removal ratio (SWRR) values (p <.05). The shortest time was obtained at 17 V/cm, while the longest time was 13 V/cm during the OE process. The EC value varies between 0.19–0.85 S/m for the voltage gradients. EC and current values increase with temperature until boiling starts, then decrease, and the EC value tends to increase slightly. The TPC value ranged between 587.4–716,4 mg GAE/100 g and was higher at OE than in the conventional process. As a result, the OE process preserves the TPC value of apple juice better while shortening the processing time. Novelty impact statement: The ohmic evaporation process is an alternative method that can be preferred in concentrating fruit juices with consuming less energy and obtaining higher quality products. In addition, considering the phenolic distribution, it was determined in this study that the products were better preserved in the ohmic evaporation process. It is predicted that it will provide important data for both pilot and industrial designs for the establishment of any ohmic evaporation systems.
AtıfScopus6WoS5OpenAlex9İncele - MakaleYalnız künye2022Scopus SJRQ2Performance evaluation of pectin extraction from grapefruit peel powder by ohmic heating
Goksu, Ali; Duran, Gülseven; Çilingir, Seda; Çevik, Mutlu; Sabanci, Serdal
This study is to investigate the performance properties during the extraction of pectin from grapefruit peel powder using ohmic heating. Pectin extraction was carried out under different voltage gradients (7–11 V/cm), different solid: liquid ratios (1:20–1:60), and different holding times (0–180 min) at constant pH and temperature (80°C). The voltage gradient and solid: liquid ratio affected the time to reach the target temperature. The highest energy efficiency value for all voltage gradients and solid: liquid ratios were obtained in the 0 min holding time, and the efficiency value, which changed between 89.47% and 56.02%, was negatively affected by the increase in the holding time. The exergy efficiency was lower than the energy efficiency and decreased due to the increasing holding time and decreasing voltage gradient. Also, the exergy efficiency was found to be between 73.69% and 18.09%. Determining the performance characteristics of the system will make a significant contribution to pilot and industrial-scale system/process applications for the future. Practical application: In this study, pectin was successfully obtained from grapefruit powder using an ohmic heating system. The operating conditions for the obtained pectin include constant pH (pH:1) and temperature (80°C) but various voltage gradients, solid: liquid ratios, and extraction times. It has been observed that voltage gradient and extraction time were effective on energy efficiency. When looking at exergy efficiency, voltage gradient, solid: liquid ratio, and extraction time were effective. It has been observed that the improvement potential (IP) value calculated for the system decreases depending on the increasing voltage gradient. The results obtained in this study are thought to be an important data source for literature, pilot, and industrial-scale production systems. It has been realized that ohmic heating, which is increasingly used, is an alternative technique for pectin production.
AtıfScopus13WoS12OpenAlex16İncele - 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 Dizin1İncele - MakaleYalnız künye2021Scopus SJRQ2Investigation of time effect on pectin production from citrus wastes with ohmic heating assisted extraction process
Sabanci, Serdal; Çevik, Mutlu; Göksu, Ali
Pectin is usually extracted by exposure to a high temperature and a specific pH value by conventional methods. However, due to reasons such as low energy efficiency of the process and damage to the pectin, alternative thermal and non-thermal methods are used in the pectin extraction process. In this study, the effect of different processing times (0, 5, 15, 30, 60, 120, 180 min) on pectin extraction was investigated for grapefruit, lemon, and orange samples at 80°C. Besides, it was determined that the electrical conductivity value ranged between 1.46–2.06 S/m during heating, the electrical conductivity value of the pH solution adjusted with sulfuric acid. Accordingly, it was figured out that the total amount of energy consumed increases as the process holding time increases. However, it was determined that there was a decrease in the average power value by turning on–off the system. Practical Application: Pectin is one of the additives used in many areas in the food industry. Pectin is now produced especially from agricultural waste peel. During this production, it is subjected to long processes at certain pH and certain temperatures. With the present study, determination of pectin yield over a wide period of time by using ohmic heating process and total ohmic heating energy was determined. In this way, it is thought that a serious contribution will be made to the literature and industry regarding different industrial agricultural waste peel (orange, grapefruit, lemon) during pectin production.
AtıfScopus36WoS31OpenAlex36İncele - MakaleYalnız künye2021Scopus SJRQ1Production of Pectin from Lemon Peel Powder Using Ohmic Heating-Assisted Extraction Process
Çilingir, Seda; Goksu, Ali; Sabanci, Serdal
The ohmic heating process is known as homogeneous, efficient, and rapid heating. In the present study, it was aimed to analyze the extraction of pectin from lemon peel using ohmic heating, to evaluate the specific pectin production coefficient (SPPC, mg/kJ) and compared it with traditional pectin production (TPP). The extraction process was carried out at 3 different temperatures (70–90 °C), 3 different solid:liquid ratios (1:30, 1:40, 1:50 g/ml), 3 different extraction holding times (0–30 min), and a constant pH (pH 2 that adjusted with citric acid). From the results, extraction conditions affected the pectin yield. As the temperature and extraction holding time increased, the pectin yields increased. In general, the 30-min pectin yields of the ohmic heating-assisted extraction (OHAE) process were similar to the pectin yields obtained from the TPP under the same conditions. Performance evaluation of pectin production was made for 90 °C, and energy efficiency was found to be over 69% for 3 different solid to liquid ratios. It has been stated that as an alternative to the TPP method, the OHAE process can be applied.
AtıfScopus50WoS44OpenAlex53İncele - 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 - MakaleAçık Erişim2020Sucuk Örneklerinin Ohmik Pişirilmesi Sırasında Elektrik İletkenlik Değerinin ve Pişirme Homojenliğinin İncelenmesi
Sabanci, Serdal
Sucuk, Türk toplumu için önemli bir geleneksel et ürünüdür ve kahvaltıda, ızgarada, günlük yemeklerde ve tostta kullanılmaktadır. Sucuk örnekleri, sekiz farklı voltaj gradyanı kullanılarak ohmik ısıtma ile 80 °C'ye kadar ısıtılarak pişirilmiştir. Ohmik pişirme sırasında voltajın artması nedeniyle pişirme işleminin süresi kısalmıştır. Ayrıca, ohmik pişirme sırasında sıcaklık arttıkça elektriksel iletkenlik değerinin arttığı ve elektrik iletkenlik değerinin 0.51-3.38 S m-1 arasında değiştiği tespit edilmiştir. Ohmik pişirme işlemi sonunda numunelerin sıcaklık homojenliği termal kamera yardımı ile incelenmiş ve düşük voltaj gradyanlarında homojen pişirme sağlanamadığı tespit edilmiştir. Sonuç olarak sucuk örneklerinin ohmik pişirme ile pişirilebileceği ve yüksek voltaj gradyanında homojen pişirme sağlanabileceği belirlenmiştir.
AtıfOpenAlex2TR Dizin1İncele - MakaleAçık Erişim2020Application of Electrical Heating Method for Grape Juice; Ohmic Heating
Sabanci, Serdal
The application of current electrical heating processes is increasing with the developing technology. One of the current electrical heatingmethods as an alternative to the traditional heating process is Ohmic heating. Ohmic heating process is based on the heating principlethat depends on the heat generation in the product by passing alternating current from the solid / liquid substance. Ohmic heating isregarded as a particularly fast, homogeneous and efficient heating. In the present study, with the help of ohmic heating process (13 V /cm at constant voltage gradient), the grape juice is heated from 20 °C to 90 °C and kept at a constant temperature for 4 differentprocessing times (0, 20, 40 and 60 min.) It was aimed to examine some quality characteristics of grape juice. In addition, it was purposedto examine the electrical conductivity value, which is one of the important properties for ohmic heating during the process, and todetermine the total spent energy value for the waiting time at different constant temperature (90 °C). While the heating time of grapejuice from 20 °C to 90 °C was determined as 311 ± 5.01 s, it was stated that the temperature change due to time has a linear trend. Inaddition, it has been determined that as the temperature increases, the electrical conductivity value increases. It has been found that theelectrical conductivity value of grape juice during the heating process varies between 0.144-0.582 S / m. In addition, during the ohmicheating application, as the holding time increases, the total consumed energy value increases but the average power value decreases.The changes in some quality characteristics during the heating of grape juice and holding at constant temperature were investigated. Itwas determined that the amount of Total Phenolic Content (TFC), which is particularly sensitive to heat treatment, in grape juice duringthe heating and waiting periods was between 466-367 mg/L in terms of Galic acid equivalent. In addition, it was found that thehydroxymethylfurfural (HMF) content of grape juice was between 0.60-4.71 ppm depending on the process of holding at differentconstant temperature. As a result, it was concluted that it influences the TFC amount and HMF content, which are among the qualitycriteria, on the waiting time at 90 °C (p <0.05).
- 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 - 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