scholarly journals The effect of ohmic heating pretreatment on drying of apple

2018 ◽  
Author(s):  
Aslı Isci ◽  
Naciye Kutlu ◽  
Merve Silanur Yilmaz ◽  
Hicran Arslan ◽  
Ozge Sakiyan
Keyword(s):  
Thin Layer ◽  
Ohmic Heating ◽  
Order Kinetic ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Kinetic ◽  
Apple Slices ◽  
Order Kinetic Model ◽  
Drying Rates ◽  
Kinetics Of

In this study, effects of ohmic pretreatment on the drying rates and color kinetics of apple were investigated. Apple slices were treated at different electric field strengths (20-30 and 40 V/cm) at 60°C for 1 min. Drying process was applied at 60˚C-2 m/s by using a tray-dryer. ΔE and moisture content were calculated. These values were fitted to the semi-theoretical thin-layer drying and the zero and first-order kinetic model. The shortest drying time was found samples treated with 30 V/cm. Wang&Singh model gave the superior fit to the experimental data. ΔE fitted well to the zero-order kinetic model.Keywords: Ohmic heating, drying, kinetic models, thin-layer models, apple.  

Influence of Drying Conditions and Mathematical Models on the Thin-Layer Drying of Mushrooms

2014 ◽  
Author(s):  
A. Stegou-Sagia ◽  
D. V. Fragkou
Keyword(s):  
Mass Transfer ◽  
Thin Layer ◽  
Mathematical Models ◽  
Drying Methods ◽  
Suitable Model ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Drying Models ◽  
Drying Rates

In the present research, experimental data from several studies about drying behavior of mushrooms have been selected and used to compare different drying methods and different mathematical thin layer drying models to simulate mushroom drying rates. The white button (Agaricus Bisporus), the oyster (Pleurotus Ostreatus) and the milky mushroom slices have been considered for drying in different dryers such as hot air cabinet dryer and fluidized bed dryer with different slice thicknesses, drying air temperatures (45 °C to 90 °C) and drying air velocities (0.2 m/s to 5 m/s). The entire drying process has taken place in the falling rate period, assuming that internal mass transfer occurred by diffusion in mushroom slices. The study shows that the drying air temperature and the drying air velocity have an effect on the moisture removal from mushrooms and also on the drying time. Mathematical models have been proved to be useful for design and analysis of heat and mass transfer during drying processes. All the drying models considered in this study could adequately represent the thin layer drying behavior of mushrooms. Furthermore, as it is obvious, any type of mushrooms has its own most suitable model.

scholarly journals The Experimental Research of Drying Kinetics of Nagpur Orange Fruit (Citrus Sinesis- L) by Hot Air Electrical Dryer

2019 ◽  
Vol 8 (6S4) ◽  
pp. 1131-1134
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Orange Fruit ◽  
Kinetics Of

The study is aimed experimentally and compared with the theoretical results of drying kinetics of Nagpur orange fruit dried in a hot air electrical dryer. Orange fruit is highly perishable and needs to be consumed or processed immediately after harvest. Drying or dehydration is one of the most practical methods of preserving food products. Therefore, thin layer drying characteristics of falling rate of Nagpur orange are determined experimentally under different conditions of drying air temperatures, relative humidity and air velocities for different moisture contents. Thin layer models like Wang and Singh, Page and Henderson have been compared with Experimental results. The knowledge of drying kinetics helps for identification of exact drying time and air flow velocity for different moisture content. Here drying operation is carried out at a velocity of 1m/sec and 1.25 m/sec for different temperature of 55°C, 65°C and 75°C. This analysis reveals that drying temperature has a more significant effect on moisture removal while velocity has the least effect. Drying rate is found to increase with the increase in drying temperature and reduce with drying time. Experimental data is statistically correlated by plotting the drying characteristics curve. The analysis reveals that Wang and Singh's model is a better model to explain the drying behavior of Nagpur Orange fruit (R2=0.9888).

scholarly journals Thin layer drying kinetics of lemon verbena leaves: a quality assessment and mathematical modeling

2021 ◽  
Vol 13 (1) ◽  
pp. 59-72
Author(s):  
Javid Ghasemi ◽  
Mehdi Moradi ◽  
Sayed Hossein Karparvarfard ◽  
Mohammad Taghi Golmakani ◽  
Amin Mousavi Khaneghah
Keyword(s):  
Essential Oil ◽  
Thin Layer ◽  
Drying Kinetics ◽  
Oil Yield ◽  
Air Velocity ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Kinetics Of ◽  
Essential Oil Yield ◽  
Lemon Verbena

The thin-layer drying kinetics of lemon verbena leaves were studied by using a solar cabinet dryer at air tempera-ture (at three levels of 30, 40, and 50°C), air velocity (at three levels of 2, 2.5, and 3 m/s), and mesh tray size (3, 6, and 10 mm). A completely randomized factorial design was used to analyze the effect of independent factors on drying time and essential oil yield. Results showed that all experiments have shorter drying time and higher essen-tial oil content than the shade-drying method. Also, the best drying conditions that led to an optimal essential oil yield (1.73 mL/g DM) involved a lower temperature (30°C) and velocity (2 m/s) and a mesh size of 10 mm. A good adaptation between the experimental and the predicted moisture content was observed, whereby the statistical criteria of R2, root mean square error, and k2 were calculated as 0.99, 0.08, and 0.01, respectively. Practical applicationsIn the current study, the effect of different drying states such as air velocity and drying temperature was studied on the drying behaviors and essential oil contents of lemon verbena leaves. The obtained results can lead us to a suitable drying condition that can be used in the subsequent designation of systems. Also, a mathematical model for the pre-diction of the leaves’ drying kinetics was constructed and evaluated, which could be approached in the drying systems.

scholarly journals Drying Kinetics of Sliced Pineapples in a Solar Conduction Dryer

2017 ◽  
Vol 7 (2) ◽  
pp. 14 ◽  
Author(s):  
Luqman Ebow Ibn Daud ◽  
Isaac Nyambe Simate
Keyword(s):  
Thin Layer ◽  
Average Moisture Content ◽  
Drying Time ◽  
Sun Drying ◽  
Thin Layer Drying ◽  
Drying Models ◽  
Drying Model ◽  
Thin Layer Drying Models ◽  
Drying Curves ◽  
Kinetics Of

As a means of adding value to pineapple production and minimising post-harvest losses, sliced pineapples were dried using a Solar Conduction Dryer (SCD) and appropriate thin layer drying models to predict drying were developed whilst the performance of the SCD was also investigated. For the period of the experiment, ambient temperature and temperature in the dryer ranged from 24 to 37 °C and 25 to 46 ℃ respectively. The performance of the dryer was compared to open sun drying using pineapple slices of 3-5 mm in thickness where the slices were reduced from an average moisture content of 85.42 % (w.b.) to 12.23 % (w.b.) by the SCD and to 51.51 % (w.b.) by the open sun drying in 8 hours effective drying time. Pineapple slices of thicknesses 3 mm, 5 mm, 7 mm and 10 mm were simultaneously dried in the four drying chambers of the SCD and their drying curves simulated with twelve thin layer drying models. The Middilli model was found as the best fitted thin layer drying model for sliced pineapples. The optimum fraction of drying tray area that should be loaded with pineapples was also investigated by simultaneously loading 7 mm slices of pineapples at 50, 75, and 100 percent of drying tray area. Loading the slices at 50, 75 and 100 percent of drying tray area gave overall thermal efficiencies of 23, 32 and 44 percent, respectively, hence loading pineapple slices at 100 percent drying tray area was recommended as the best.

Mathematical Modeling of Thin Layer Drying Kinetics of Apple in Tunnel Dryer

2008 ◽  
Vol 4 (8) ◽  
Author(s):  
Raj Kumar Goyal ◽  
Mujjeb O ◽  
Vinod Kumar Bhargava
Keyword(s):  
Thin Layer ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Tunnel Dryer ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Apple Slices ◽  
Drying Models ◽  
Drying Behaviour ◽  
Kinetics Of

In this study, the drying kinetics of apple (control, blanching and blanching in 1% potassium meta bisulphate) in a tunnel dryer was studied at 50, 60, and 70°C air temperatures. The drying of apple slices occurred in a falling rate period. It was found that treated apple slices dried faster. Six thin layer-drying models were fitted to the experimental moisture ratio. Among the mathematical models evaluated, the logarithmic model satisfactorily described the drying behaviour of apple slices with high r2 values. The effective moisture diffusivity (Deff) of apple slices increased as the drying air temperature increased. The Deff values were higher for the treated samples than for the control.

scholarly journals Thin-Layer Drying Characteristics and Modeling of Chinese Jujubes

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Xiao-Kang Yi ◽  
Wen-Fu Wu ◽  
Ya-Qiu Zhang ◽  
Jun-Xing Li ◽  
Hua-Ping Luo
Keyword(s):  
Thin Layer ◽  
Distribution Model ◽  
Drying Time ◽  
Drying Characteristics ◽  
Simulation And Optimization ◽  
Thin Layer Drying ◽  
Drying Models ◽  
Higher Temperature ◽  
Drying Rates ◽  
Experimental Values

A mathematical modeling of thin-layer drying of jujubes in a convective dryer was established under controlled conditions of temperature and velocity. The drying process took place both in the accelerating rate and falling rate period. We observed that higher temperature reduced the drying time, indicating higher drying rates of jujubes. The experimental drying data of jujubes were used to fit ten different thin-layer models, then drying rate constants and coefficients of models tested were determined by nonlinear regression analysis using the Statistical Computer Program. As for all the drying models, the Weibull distribution model was superior and best predicted the experimental values. Therefore, this model can be used to facilitate dryer design and promote efficient dryer operation by simulation and optimization of the drying processes. The volumetric shrinkable coefficient of jujubes decreased as the drying air temperature increased.

scholarly journals Modelagem matemática para a descrição da cinética de secagem do fruto da palma (Opuntia fícus indica)

2016 ◽  
Vol 11 (1) ◽  
pp. 01
Author(s):  
A. E. Santos ◽  
G. M. V. Martins ◽  
M. F. C. S. Canuto ◽  
J. E. D. Vieira Segundo ◽  
R. D. Almeida
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Coefficient Of Determination ◽  
Font Size ◽  
Drying Time ◽  
Palm Fruit ◽  
Opuntia Ficus Indica ◽  
Thin Layer Drying ◽  
Kinetics Of ◽  
Background Image

<p>O presente trabalho teve como objetivo estudar a secagem em camada fina do fruto da palma (<em>Opuntia fícus indica</em>) nas temperaturas de 50, 60 e 70 °C em estufa com circulação forçada de ar. Foram empregados os modelos matemáticos de Aproximação da difusão, Logaritmico, Midilli e Page. Como critério de avaliação utilizou-se o coeficiente de determinação e o desvio quadrático médio (). Mediante os resultados obtidos observou-se que o aumento da temperatura diminuiu o tempo de secagem do fruto. Dentre os modelos aplicados o Logarítmico apresentou os maiores valores de coeficiente de determinação R² e os menores valores de DQM para a faixa de temperatura e espessura estudadas.</p><p class="MsoNormal" style="margin-bottom: 0.0001pt; text-align: center;" align="center"><strong><em><span style="font-size: 14pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US">Mathematical modeling for description of the pulp drying kinetics of palm fruit (Opuntia fícus indica)</span></em></strong></p><p class="MsoNormal" style="margin-bottom: 0.0001pt;"><span style="font-size: 9pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US"> </span></p><p> </p><p class="MsoNormal" style="margin-bottom: 0.0001pt; text-align: justify;"><strong><span style="font-size: 10pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US">Abstract</span></strong><span style="font-size: 10pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US">: This work was developed with the aimed of to study ing the thin layer drying of palm fruit pulp oiti at temperatures of 122, 140 and 158 °Fahrenheit in an oven with forced air circulation. For the representation of the drying kinetics of thin-layer were used mathematical  models of the diffusion approximation, logarithmic, and Midilli Kucuk and Page, and as a criterion for evaluating these we used the coefficient of determination and the deviation quadratic mean (DQM). From tThe results obtained showed that the increase in temperature decreases the drying time of the palm fruit. Among the models applied to Logarithmic the had the highest R2 values and lower values of DQM for the temperature and layer thickness range studied.</span></p><br /><strong></strong><p class="MsoNormal" style="margin-bottom: 0.0001pt; text-align: center;" align="center"> </p>

scholarly journals Thin layer mathematical modelling of white maize in a mobile solar-biomass hybrid dryer

2021 ◽  
Author(s):  
Joseph Oppong Akowuah ◽  
Ato Bart-Plange ◽  
Komla A. Dzisi
Keyword(s):  
Thin Layer ◽  
Type Equation ◽  
Moisture Diffusivity ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Mean Square ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Behaviour ◽  
Kinetics Of

Performance of a tractor mounted solar-biomass hybrid dryer which utilise combined energy of solar and biomass was investigated. Drying behaviour of maize grains in the dryer was also investigated using 10 thin-layer mathematical models. The models were compared based on coefficient of determination (R<sup>2</sup>) and root mean square error (RMSE) values between experimental and predicted moisture ratios. Moisture content (MC) of grains in the dryer reduced from 19 ± 0.86% to 13 ± 0.4% (w.b.) in 5 h, compared to grains dried in open-sun which reached same MC in 15 hours. This resulted in average drying rate of 1.2 %·h<sup>–1</sup> compared to 0.4 %·h<sup>–1</sup> for grains dried in the open-sun leading to net savings in drying time of 67%. Overall mean temperature, 41.93 ± 2.7 °C in the dryer was 15.3 °C higher than the ambient temperature. Midilli Kucuk model was best to describe the thin-layer drying kinetics of maize in the dryer. It showed a good fit between the predicted and experimental data. The effective moisture diffusivity of grains dried in the dryer ranged between 1.45 × 10<sup>–11</sup> m<sup>2</sup>·s<sup>–1</sup> – 3.10 × 10<sup>–11</sup> m<sup>2</sup>·s<sup>–1</sup>. An activation energy of 96.83 kJ·mol<sup>–1</sup> was determined based on the Arrhenius-type equation.

scholarly journals Sorption equilibrium and kinetics of thin-layer drying of green bell peppers

2018 ◽  
pp. 137
Author(s):  
Olga R.R. Gandolfi, Ramos Ferreira Goncalves ◽  
Renata C. F. Bonomo, Rafael daCosta I. Fontan
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Equilibrium Moisture Content ◽  
Air Velocity ◽  
Drying Time ◽  
Sorption Data ◽  
Page Model ◽  
Thin Layer Drying ◽  
Bell Peppers ◽  
Kinetics Of

Drying is a unit operation widely used in food preservation. It is important to know how this process takes place and the effects of variables such as temperature, relative humidity and air velocity. It is also essential to know the equilibrium moisture content of the product at the temperature under study. Thus, the objective of this study was to determine the sorption isotherms and evaluate the effects of temperature (60°C and 75°C) and air velocity (1.5 m s-1 and 3.0 m s-1) on the thin-layer drying curves of green bell peppers. The experimental sorption data were adjusted to the BET and GAB models, where the latter best described the sorption behavior of the pepper. It was also verified that with the elevation in temperature lower values for the equilibrium moisture content were obtained. The drying data were adjusted to the Page model, Henderson and Pabis model, Newton model and Fick model. From the latter model the effective diffusion coefficient of water in the project was determined, confirming that the increase in temperature did not increase with greater air velocity. The Page model was that which best fit to all drying conditions. The variation in drying air velocity little affected the kinetics of the process, observing only a small reduction in drying time with increased air velocity (approximately 2.4%), while temperature showed the greatest influence, with a large reduction in drying time with increase in this variable (around 41.4%).

scholarly journals Solar Tunnel Drying: Pretreatment on drying kinetic of plum tomatoes

2019 ◽  
Vol 49 (7) ◽  
Author(s):  
Sevil Karaaslan ◽  
Kamil Ekinci ◽  
Barbaros Salih Kumbul
Keyword(s):  
Thin Layer ◽  
Solar Irradiation ◽  
Nacl Solution ◽  
Color Analysis ◽  
Drying Time ◽  
Tunnel Dryer ◽  
Drying Kinetic ◽  
Drying Behavior ◽  
Drying Rates ◽  
Fresh Tomato

ABSTRACT: Drying of thin layer tomato was studied using a solar tunnel dryer under the ecological conditions of Isparta, Turkey. During drying process, solar irradiation, drying air temperature, relative humidity, and air velocity were measured constantly in different parts of the dryer. Drying runs were performed using plum tomatoes, characterized by an oval shape, intense red color. The change of tomatoes mass was measured daily. The color measurements of dried products were determined at the beginning and end of experiment. In this study, the fresh tomato samples were sorted, graded, washed in water and then sliced into quarters and halves before pretreated. Sun drying behavior of half and quarter sliced tomatoes pretreated with 10% NaCl solution and non-pretreated was investigated. Results showed that the drying time for pretreated and non-pretreated samples was not significantly different. However, drying time and drying rates were affected by number of tomato slices (quarter and half). Drying characteristic curves were evaluated against thirteen mathematical models and the Midilli et al model was the best descriptive model for solar tunnel drying of thin layer tomato. Color analysis emphasized that if tomatoes are pretreated with 10% NaCl solution, they should be sliced in quarter for better quality.

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