Drying Kinetics of Osmotically Pre-Treated Plum Tomato Pieces

2008 ◽  
Vol 4 (8) ◽  
Author(s):  
Marianne S Brooks ◽  
Abdel E Ghaly ◽  
Nabiha H Abou El-Hana
Keyword(s):  
Sample Size ◽  
Cell Walls ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Moisture Ratio ◽  
Air Drying ◽  
Rate Period ◽  
Pre Treatment ◽  
Kinetics Of ◽  
Over Time

The air-drying kinetics of plum tomato pieces pre-treated with different osmotic solutions were investigated. Four pre-treatment solutions (comprised of salt, sugar and/or calcium lactate), three sample geometries (halves, quarters and eighths) and two air-drying temperatures (55 and 65°C) were studied. In general, the rate of drying over time appeared to fit an exponential curve (R2 values between 0.74 and 0.99). A closer look at the data indicated that the rate of drying appeared to follow two separate falling rate periods. The change from one falling rate period to another was observed for samples at a transition moisture ratio of ~ 0.2, for all geometries and temperatures. Thus, modeling the process was improved by including the two falling rate periods. The drying constant (K) for the two falling rate periods ranged between 0.05 to 0.3 h-1. Moisture diffusivity values ranged from 2.5 x 10-9 to 9 x 10-9 m2 s-1 and were relatively constant during the first falling rate period. During the second falling rate period, the diffusivity increased as the moisture ratio decreased, though this change was less pronounced as the sample size decreased from halves to eighths. The untreated samples had lower diffusivities than those with osmotic pre-treatment but there were no differences amongst the various pre-treatment solutions. In general, moisture diffusivities showed a dependence on the sample size, as the larger tomato samples had higher values of diffusivity. The greater diffusivity seen in the larger samples may be due to the collapse of cell walls in the skin.

Effect of the Osmotic Pre-Treatment on the Convective Air Drying Kinetics of Pear Var. Blanquilla

2006 ◽  
Vol 9 (3) ◽  
pp. 541-549 ◽  
Author(s):  
C. González-Martínez ◽  
M. Cháfer ◽  
K. Xue ◽  
A. Chiralt
Keyword(s):  
Drying Kinetics ◽  
Air Drying ◽  
Pre Treatment ◽  
Kinetics Of

Influence of Microwave Osmotic Dehydration Pre-Treatment on the Second Stage of Air-Drying Kinetics of Apples

2011 ◽  
Vol 7 (3) ◽  
Author(s):  
Elham Azarpahzooh ◽  
Hosahalli S. Ramaswamy
Keyword(s):  
Energy Savings ◽  
Osmotic Dehydration ◽  
Sucrose Concentration ◽  
Drying Kinetics ◽  
Drying Time ◽  
Air Drying ◽  
Second Stage ◽  
Freeze Dried ◽  
Pre Treatment ◽  
Kinetics Of

The effect of microwave-osmotic dehydration pre-treatment under continuous flow medium spray (MWODS) conditions on the second stage air-drying kinetics of apple (Red Gala) cylinders was evaluated. MWODS pre-treatment was carried out using a response surface methodology involving 5-levels of sucrose concentration (33-66.8°B), temperature (33-66.8°C) and contact time (5-55 min). Drying time and coefficient of moisture diffusion (Dm) and coefficient of moisture infusion (Im) during rehydration were evaluated as responses and the results were compared with their air-dried (AD) (worst scenario) and freeze-dried (FD) (best scenario) counterparts without the osmotic treatments. The diffusion and infusion coefficients were based on the solution of Fick's diffusion model. Empirical models developed for all response variables were significant (P ? 0.001) and the lack of fit was not significant (P > 0.05). MWODS pre-treatments significantly influenced the Dm values and reduced the air-drying time of apples by 30-65 percent in comparison with untreated apple thereby providing opportunity for better energy savings. On the other hand, the values of Im during the rehydration process were highest for the freeze-dried samples followed by apples air-dried after MWODS treatment, and the least for the untreated air-dried samples.

scholarly journals Drying Kinetics of Eggplant (Solanum melongena) in a Fluidized Bed Dryer: Experimental Evaluation and Modelling

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed A. ElKhodiry ◽  
Shaima R. Suwaidi ◽  
Melika Taheri ◽  
Hams Elwalid ◽  
Dina ElBaba ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Solanum Melongena ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Moisture Ratio ◽  
Air Velocity ◽  
Rehydration Ratio ◽  
Fluidized Bed Dryer ◽  
Ratio Data ◽  
Kinetics Of

The drying kinetics of eggplant were studied experimentally in a laboratory-scale fluidized bed dryer. Experiments were conducted at drying temperatures of 60, 70, and 80°C and at constant air velocity of 3.10 ms−1. The drying rate and moisture ratio were determined as a function of time. At any given temperature, only the falling rate period was observed during the drying process. Effective moisture diffusivity was in the range 2.667–4.311 × 10−8 m2/s while activation energy of 23.5 kJ mol−1 was obtained from the Arrhenius equation. The experimental moisture ratio data was fitted to ten mathematical models. Statistical analysis showed that the by Demir et al. has the best fit quality. In terms of product quality, the dried samples had low rehydration ratio of 4.889. In addition, compared to direct sunlight drying, the dried product from the fluidized bed dryer exhibited better color quality.

scholarly journals Empirical Modeling of Hot Air-Drying Kinetics of Horseradish Dehydration

2020 ◽  
Vol 4 (1) ◽  
pp. 44
Author(s):  
Mukesh Guragain ◽  
Pranabendu Mitra
Keyword(s):  
Moisture Content ◽  
Empirical Models ◽  
Drying Kinetics ◽  
Hot Air Drying ◽  
Air Drying ◽  
Drying Temperature ◽  
Hot Air ◽  
Rate Period ◽  
Drying Conditions ◽  
Kinetics Of

The preservation of perishable horseradish crop is essential to increase the shelf-life and supply year-round. Hot air-drying method is commercially viable for preserving fruits and vegetables. However, drying conditions such as drying temperature affect the drying kinetic and the final quality of dried products. It is necessary to understand how drying temperature and blanching affect the drying kinetics of horseradish for the prediction of the right drying conditions. The objective of this study was to investigate the hot air-drying kinetics by fitting commonly used five empirical models to establish right hot air-drying conditions for drying of horseradish. The unblanched (control, C) and blanched (B) horseradish slices were dried at 50, 70 and 85℃ until reaching to an equilibrium moisture content (db). The moisture reduction data were collected at certain intervals and the moisture content data were converted to moisture ratio (MR). The MR data were used to predict the drying kinetics of horseradish drying using five empirical models. The results indicated that drying kinetics followed the constant drying rate period and falling rate period for all three drying temperatures. The five tested models were able to predict the drying kinetics with R2 (0.96-0.99) and RMSE (0.01-0.06) depending on the models and blanching. However, diffusion approach model was the best fitted model securing the highest R2 and the lowest RMSE. The findings of this research are expected to be significantly important for horseradish drying effectively.

scholarly journals Effect of ultrasound pre-treatment on the drying kinetics of brown seaweed Ascophyllum nodosum

2015 ◽  
Vol 23 ◽  
pp. 302-307 ◽  
Author(s):  
Shekhar U. Kadam ◽  
Brijesh K. Tiwari ◽  
Colm P. O’Donnell
Keyword(s):  
Brown Seaweed ◽  
Ascophyllum Nodosum ◽  
Drying Kinetics ◽  
Pre Treatment ◽  
Kinetics Of

HOT-AIR DRYING AND MODELING THE DRYING KINETICS OF SUNFLOWER (HELIANTHUS ANNUS L.) PETALS

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Amir Hossein Mirzabe ◽  
◽  
Gholam Reza Chegini ◽  
Keyword(s):  
Economic Value ◽  
Cost Effective ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Sunflower Seeds ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Helianthus Annus ◽  
Air Dryer ◽  
Kinetics Of

Sunflower seeds and oil in food and agricultural processing are of great importance. Dried sunflower petals are the most important parts of the sunflower plant that have economic value. Thin-layer drying experiments were performed in a laboratory scale hot-air dryer. The results indicated that with increasing drying temperature and air velocity, time of drying reduces and in most cases, the logarithmic model had the best performance for modeling the drying kinetics. The calculated values of the effective moisture diffusivity varied from 3.16627 ×10-13 to 1.32860 ×10-12 m2 s-1 and the values of the activation energy for air velocities of 0.4 and 0.8 m s-1 were equal to 51.21 and 42.3 kJ mol-1, respectively. Also, to verify whether the production and sale of sunflower petals can be cost effective, economic analysis was done. This analysis showed that drying of sunflower petals is profitable process and the generated revenue can even surpass the revenue from the sale of sunflower seeds.

Mathematical modeling of hot-air drying kinetics of red bell pepper (var. Lamuyo)

2007 ◽  
Vol 79 (4) ◽  
pp. 1460-1466 ◽  
Author(s):  
A. Vega ◽  
P. Fito ◽  
A. Andrés ◽  
R. Lemus
Keyword(s):  
Mathematical Modeling ◽  
Drying Kinetics ◽  
Bell Pepper ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Kinetics Of

Modeling the Electrohydrodynamic (EHD) Drying of Banana Slices

2016 ◽  
Vol 12 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Kianoosh Pirnazari ◽  
Ali Esehaghbeygi ◽  
Morteza Sadeghi
Keyword(s):  
Moisture Transfer ◽  
Moisture Diffusivity ◽  
Moisture Ratio ◽  
Coefficient Of Determination ◽  
Maximum Difference ◽  
Drying Process ◽  
External Resistance ◽  
Rate Period ◽  
Maximum Coefficient ◽  
Predicted Values

Abstract Electrohydrodynamic (EHD) drying of banana slices was modeled both numerically and empirically. The drying process was conducted using the EHD technique at 6, 8, and 10 kV cm−1 with banana slices 3 mm thick. Based on the maximum coefficient of determination (R2) and minimum value of root mean square of error (RMSE) observed in the experimental and predicted values of moisture ratio, the diffusion model was identified as the best prediction model. The values for effective moisture diffusivity were calculated to be in the range of 3.12 × 10−10 to 4.23 × 10−10 m2 s−1. In addition, a theoretical model was developed using the numerical (implicit) solution of the second Fick’s equation based on low variation in the external resistance by applying EHD. Moisture ratio versus time showed a falling rate period indicating that the internal moisture transfer is dominant at EHD. Results of numerical solution showed adequate consistency with experimental data, having the maximum difference of less than 0.16 g g−1 in moisture content.

Effect of Air Velocity and Temperature on the Drying Kinetics of Drumstick Leaves (Moringa Oleifera)

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Monica Premi ◽  
Harish Sharma ◽  
Ashutosh Upadhyay
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Moringa Oleifera ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Drying Time ◽  
Effective Moisture ◽  
Kinetics Of

Abstract The present study examines the effect of air velocity on drying kinetics of the drumstick leaves in a forced convective dryer. The drumstick leaves were dried in the temperature range of 50–800 C, at different air velocity (Dv) of 0.5 and 1.3 m/s. The results indicated that drying temperature and air velocity are the factors in controlling the drying rate. Experimental data obtained for the samples for color, drying rate and drying time proved that air velocity of 1.3 m/s yielded the product superior in terms of both quality and energy efficiency as compared to the samples at 0.5 m/s. Activation energy for drumstick leaves dried with air velocity, 0.5 and 1.3 m/s was 12.50 and 32.74 kJ/mol respectively. The activation energy relates similarly with the effective moisture diffusivity which also increased with increase in air velocity and temperature.

Water Diffusivity and Drying Kinetics of Air Drying of Figs

2009 ◽  
Vol 27 (3) ◽  
pp. 502-512 ◽  
Author(s):  
G. Xanthopoulos ◽  
S. Yanniotis ◽  
Gr. Lambrinos
Keyword(s):  
Drying Kinetics ◽  
Air Drying ◽  
Water Diffusivity ◽  
Kinetics Of
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