scholarly journals Mathematical modelling of the osmotic dehydration of physalis

2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Fernanda Rosa Assis ◽  
Rui Manuel Santos Costa de Morais ◽  
Alcina Maria Miranda Bernardo de Morais
Keyword(s):  
Mass Transfer ◽  
Atmospheric Pressure ◽  
Osmotic Dehydration ◽  
Mass Ratio ◽  
Promising Alternative ◽  
Sucrose Solutions ◽  
Mass Transfer Kinetics ◽  
Osmotic Agent ◽  
Effective Diffusivities ◽  
Best Fit

Abstract Physalis was osmotically dehydrated with 60 °Bx sucrose or sorbitol solutions at 60 °C and with a mass ratio of sample to solution of 1:4, at atmospheric pressure or under vacuum at 150 mbar. The Crank’s, Peleg’s and Page’s models were tested to describe the mass transfer kinetics for water loss (WL) and solids gain (SG). The effective diffusivities of both water and solute were around 10-11 m2 s-1 under all conditions. Peleg’s model presented the best fit. The use of sorbitol as the osmotic agent resulted in an increase in the WL rate. In experiments with sucrose solutions, a higher WL was obtained under vacuum than at atmospheric pressure. The SG was particularly low during osmotic dehydration. Thus, the use of sorbitol as the osmotic agent was shown to be a promising alternative to sucrose.

scholarly journals Quality of ‘Royal Gala’ cut apple during osmotic dehydration

2020 ◽  
Vol 23 ◽  
Author(s):  
Bert Pieters ◽  
Fernanda Rosa Assis ◽  
Rui Manuel Santos Costa Morais ◽  
Alcina Maria Miranda Bernardo Morais
Keyword(s):  
Atmospheric Pressure ◽  
Phenolic Content ◽  
Osmotic Dehydration ◽  
Quality Parameters ◽  
Total Phenolic ◽  
Color Changes ◽  
Sucrose Solutions ◽  
Osmotic Agent ◽  
Best Fit

Abstract The present work aimed to evaluate quality parameters of ‘Royal Gala’ apple cubes during osmotic dehydration (OD). We investigated the following OD conditions: osmotic agent, pressure, and temperature. The osmotic agent, being lower after OD with sorbitol than sucrose solutions, mainly influenced the water activity of the product. The color changes increased with increased temperature and were higher in vacuum experiments than at atmospheric pressure. In general, we recommend OD at 25 °C and atmospheric pressure for the preservation of the total phenolic content (TPC) and antioxidant activity (AA) of apple cubes during the process. Peleg’s model was found to provide the best fit of TPC and AA data.

scholarly journals Vacuum-Assisted Osmotic Dehydration of Autumn Olive Berries: Modeling of Mass Transfer Kinetics and Quality Assessment

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2286
Author(s):  
Mohamed Ghellam ◽  
Oscar Zannou ◽  
Charis M. Galanakis ◽  
Turki M. S. Aldawoud ◽  
Salam A. Ibrahim ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Water Loss ◽  
Atmospheric Pressure ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
Vacuum System ◽  
Pressure System ◽  
Solid Gain ◽  
Autumn Olive ◽  
Mass Transfer Kinetics

Autumn olive fruits were osmo-dehydrated in sucrose solution at 70 °C under vacuum and atmospheric pressure. The mass transfer kinetics data were applied to the models of Azuara, Crank, Page, and Peleg. The Peleg model was the best-fitted model to predict the water loss and solid gain of both treatments. The vacuum application decreased the effective diffusivities from 2.19 × 10−10 to 1.55 × 10−10 m2·s−1 for water loss and from 0.72 × 10−10 to 0.62 × 10−10 m2·s−1 for sugar gain. During the osmotic dehydration processes, the water activity decreased and stabilized after 5 h, while the bulk densities increased from 1.04 × 103 to 1.26 × 103 kg/m3. Titratable acidity gradually reduced from 1.14 to 0.31% in the atmospheric pressure system and from 1.14 to 0.51% in the vacuum system. pH increased significantly in both systems. Good retention of lycopene was observed even after 10 h of treatments. For the color parameters, the lightness decreased and stabilized after 30 min. In comparison, the redness and yellowness increased in the first 30 min and gradually decreased towards the initial levels in the fresh fruit.

scholarly journals Osmotic dehydration of carrot in sugar beet molasses: Mass transfer kinetics

2010 ◽  
pp. 47-55
Author(s):  
Gordana Koprivica ◽  
Nevena Misljenovic ◽  
Ljubinko Levic ◽  
Lidija Jevric ◽  
Bojana Filipcev
Keyword(s):  
Mass Transfer ◽  
Sugar Beet ◽  
Atmospheric Pressure ◽  
Immersion Time ◽  
Osmotic Dehydration ◽  
Maximal Effect ◽  
Beet Molasses ◽  
Working Temperature ◽  
Sugar Beet Molasses ◽  
Mass Transfer Kinetics

The osmotic dehydration process of carrot in sugar beet molasses solutions (40, 60 and 80%), at three temperatures (45, 55 and 65?C) and atmospheric pressure, was studied. The main aim was to investigate the effects of immersion time, working temperature and molasses concentration on mass transfer kinetics during osmotic dehydration. The most important kinetic parameters were determined after 20, 40, 60, 90, 120, 180, 240 and 300 min of dehydration. Diffusion of water and solute was the most intensive during the first hour of the process and the maximal effect was observed during the first 3 hours of immersion. During the next two hours of dehydration, the process stagnated, which implied that the dehydration time can be limited to 3 hours.

Mass transfer kinetics during osmotic dehydration of bananas (Musa sapientum, shum.)

2010 ◽  
Vol 45 (11) ◽  
pp. 2281-2289 ◽  
Author(s):  
Giovana D. Mercali ◽  
Isabel C. Tessaro ◽  
Caciano P. Z. Noreña ◽  
Lígia D. F. Marczak
Keyword(s):  
Mass Transfer ◽  
Osmotic Dehydration ◽  
Musa Sapientum ◽  
Mass Transfer Kinetics

Mass transfer and kinetics of the chemical vapor deposition of SiC onto fibers

1998 ◽  
Vol 13 (8) ◽  
pp. 2251-2261 ◽  
Author(s):  
W. Jack Lackey ◽  
Sundar Vaidyaraman ◽  
Bruce N. Beckloff ◽  
Thomas S. Moss III ◽  
John S. Lewis
Keyword(s):  
Mass Transfer ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Total Flow ◽  
A Value ◽  
Factor Expression ◽  
Kinetics Of ◽  
Best Fit

An internally consistent set of data was generated for the chemical vapor deposition (CVD) of SiC from methyltrichlorosilane (MTS) and H2 at atmospheric pressure. A moving fiber tow was used as the substrate. Coating rates between 0.3 and 3.7 µm/min and deposition efficiencies between 24 and 48% were obtained for MTS and H2 flow rates in the range 30 to 200 cm3/min and 300 to 2000 cm3/min, respectively. The data were analyzed and found to be best fit under a mass transfer regime. Based on this fit, a value of the constant in the Chilton–Colburn j factor expression for a moving fiber tow was estimated to be 2.74 × 10−6 with a standard deviation of 3.2 × 10−7. The efficiency of the reaction was found to decrease with increases in the total flow rate, indicating that the effect of the decreased residence time of reagents in the reactor was larger than the increase in the mass transfer coefficient. Finally, a comparison between the efficiencies for a stationary and a moving tow revealed that the moving tow had a higher efficiency, possibly due to a disruption of the boundary layer by the tow motion or due to the decrease in the canning of the moving tow.

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