scholarly journals Osmotic Dehydration of Apples Under Reduced Pressure Conditions

2016 ◽  
Vol 20 (3) ◽  
pp. 135-143 ◽  
Author(s):  
Siemowit Muszyński ◽  
Krzysztof Kornarzyński ◽  
Bożena Gładyszewska
Keyword(s):  
Weight Loss ◽  
Weight Gain ◽  
Water Loss ◽  
Atmospheric Pressure ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
Total Weight Loss ◽  
Reduced Pressure ◽  
Pressure Application ◽  
Osmotic Solution

AbstractThe aim of the study was to determine the effect of reduced pressure on the osmotic dehydration of apples. Tests were performed under vacuum of 8 kPa, 67 kPa, 80 kPa and under the atmospheric pressure (100 kPa). The samples were dehydrated in a sucrose solution with a concentration of 30°Bx, 50°Bx and 70°Bx. It has been shown that the effect of low pressure application depends significantly to the concentration of the osmotic solution. It has been found that the overall weight change significantly depend on the concentration of the solution, and after 3 hours of dehydration at a pressure of 80 kPa at solutions of 30°Bx, 50°Bx and 70°Bx total weight loss increased by 65%, 12% and 25% respectively, when compared to samples dehydrated at atmospheric pressure. From the studied variants of reduced pressure, the pressure of 80 kPa seems to be the optimal one, as evidenced by the lowest values of weight gain to water loss ratios for apples dehydrated in solutions of 50°Bx and 70°Bx.

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 Study of osmotic dehydration of kiwi fruit using sucrose solution

2019 ◽  
Vol 22 ◽  
Author(s):  
Bethania Brochier ◽  
Juliana Mesquita Inácio ◽  
Caciano Pelayo Zapata Noreña
Keyword(s):  
Water Activity ◽  
Water Loss ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
Kiwi Fruit ◽  
Free Moisture ◽  
Sucrose Solutions ◽  
Peleg Model ◽  
Osmotic Solution ◽  
In The Beginning

Abstract Osmotic dehydration of kiwi was evaluated using 45, 55 and 65 °Brix sucrose solutions. Free moisture, water activity and solutes gain decreased in fruit during the process. Water loss rates were higher in the beginning of drying. Water activity decrease was higher when the product was in 65 °Brix solution. The equilibrium moisture content estimated by the Peleg model decreased significantly with increasing concentration of the osmotic solution, and the diffusivity values of water loss were in the range from 1.5 × 10-9 to 1.9 × 10-9 m2 s-1. The osmotic pressures of the solutions were also predicted.

Effect of Blanching and Vacuum Pulse Application on Osmotic Dehydration of Pear

2003 ◽  
Vol 9 (5) ◽  
pp. 321-328 ◽  
Author(s):  
M. Chafer ◽  
C. Gonzalez-Martinez ◽  
B. Fernandez ◽  
L. Perez ◽  
A. Chiralt
Keyword(s):  
Water Loss ◽  
Atmospheric Pressure ◽  
Transfer Rate ◽  
Osmotic Dehydration ◽  
Mass Transfer Rate ◽  
Structural Response ◽  
External Solution ◽  
Gas Release ◽  
Volume Compression ◽  
Pre Treatment

Osmotic dehydration of pear cylinders (var. blanquilla) was studied by analysing the effect of blanching pre-treatment and the application of a vacuum pulse on the kinetics and yield of the process and on product quality (colour and mechanical behaviour). Fresh and stem-blanched samples were treated with 65 Brix sucrose at atmospheric pressure and by applying a vacuum pulse (50 mbar for 5 min). The influence of the sugar gain and water loss fluxes, and the tissue structural response to the vacuum pulse, on the total mass and volume losses of the samples has been discussed. Blanching implied an increase in the mass transfer rate in pear tissue. Vacuum pulse in blanched samples resulted in more volume compression than sample impregnation with the external solution due to the sample softening by thermal effect and to the partial gas release during its thermal expansion. This provoked the greatest volume losses and a reductionof the ratio of sugar gain to water loss, where the highest values reached were for non-blanched samples submitted to vacuum pulse. Mechanical changes induced by treatments were similar inall cases, but colour hue and chrome were better preserved in samples treated by PVOD. Nevertheless, this treatment implied a transparency gain due to the sample gas release and so, samples become darker.

Optimization of Osmotic Dehydration Process of Aonla Fruit in Salt Solution

2010 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammed Shafiq Alam ◽  
Amarjeet Singh
Keyword(s):  
Vitamin C ◽  
Salt Solution ◽  
Water Loss ◽  
Osmotic Dehydration ◽  
Colour Change ◽  
Solution Temperature ◽  
Process Time ◽  
Dehydration Process ◽  
Overall Acceptability ◽  
Osmotic Solution

For optimization of osmotic dehydration process of aonla fruit in salt solution by response surface methodology, the experiments were conducted according to Box and Behnken design. The independent process variables for osmotic dehydration process were osmotic solution concentrations (5-25% w/v salt), osmotic solution temperature (30-60°C), solution to fruit ratio (4-8 v/w), and process time (60-240 minutes). The osmotic drying process was optimized for maximum water loss, overall acceptability and minimum solute gain, colour change, and vitamin-C loss. The optimum conditions were 22% salt concentration, 44.5°C osmotic solution temperature, 6.5 solution to fruit ratio, and 60 minutes process time. An analysis of variance (ANOVA) revealed that, among the process variable, concentration has the most significant effect on water loss, solute gain, and overall acceptability; solution temperature has the most effect on colour change; and process time has the most effect on vitamin-C loss whereas solution-to-fruit ratio observed significantly lower effect on responses.

Water content, weight change, and activity of apterous and alate virginoparous Acyrthosiphon pisum (Harris) (Homoptera: Aphididae)

1979 ◽  
Vol 57 (2) ◽  
pp. 363-367 ◽  
Author(s):  
P. A. MacKay ◽  
R. G. H. Downer
Keyword(s):  
Weight Loss ◽  
Weight Gain ◽  
Water Content ◽  
Water Loss ◽  
Weight Change ◽  
Acyrthosiphon Pisum ◽  
Live Weight ◽  
Mature Adults ◽  
Final Moult ◽  
Third Instar Larvae

Changes in weight, water content, and activity of alate and apterous virginoparous Acyrthosiphon pisum (Harris) were observed during development from third instar larvae to mature adults. Apterous aphids gained weight steadily until the 4th day of adulthood, and showed no dramatic changes in activity during this period. The live weights of alate aphids decreased during the 24 h immediately following the final moult, but increased gradually after this lime. The onset of weight loss occurred before the active nonfeeding period during which dispersal would normally lake place. Recommencement of weight gain followed the resumption of feeding. After the adult moult, the water content of alatae expressed as a percentage of live weight decreased for 24 h. whereas that of apterae remained constant. During the next 24 h, the water content of alatae increased to a level slightly below that of apterae. Thereafter, both morphs maintained a constant water content until about the 5th day, when a slight increase was evident. Eighty-five percent of the weight loss of adult alatae is attributable to water loss. It is suggested that dehydration of newly moulted adult alatae is an adaptation to facilitate dispersive flight.

scholarly journals Note: Application of neural network modelling for the control of dewatering and impregnation soaking process (osmotic dehydration) Nota: Aplicación del sistema de simulación de redes neurales para el control de la deshidratación osmótica

1997 ◽  
Vol 3 (6) ◽  
pp. 459-465 ◽  
Author(s):  
I.C. Trelea ◽  
A.L. Raoult-Wack ◽  
G. Trystram
Keyword(s):  
Neural Network ◽  
Mass Transfer ◽  
Water Loss ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
Network Modelling ◽  
Experimental Range ◽  
Neural Network Modelling ◽  
Underlying Mechanisms ◽  
Hidden Layer

The aim of this work was to elaborate a predictive model of the mass transfer (water loss and solute gain) that occurs during dewatering and soaking by using neural network modelling. Two separate feedforward networks with one hidden layer were used (for water loss and solute gain respectively). Model validation was carried out on results obtained previously, which dealt with agar gel soaked in sucrose solution over a wide experimental range (temperature, 30-70 °C; solu tion concentration, 30-70 g sucrose/100 g solution; time 0-500 min; agar concentration, 2-8%). The best results were obtained with three hidden neurons, which made it possible to predict mass transfer, with an accuracy at least as good as the experimental error, over the whole experimental range. The technological interest of such a model is related to a rapidity in simulation compa rable to that of a traditional transfer function, a limited number of parameters and experimental data, and the fact that no preliminary assumption on the underlying mechanisms was needed.

scholarly journals Rate of water loss and sugar uptake during the osmotic dehydration of pineapple

2005 ◽  
Vol 48 (5) ◽  
pp. 761-770 ◽  
Author(s):  
Laura A. Ramallo ◽  
Rodolfo H. Mascheroni
Keyword(s):  
Moisture Content ◽  
Linear Function ◽  
Water Loss ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
Efficiency Index ◽  
Sugar Uptake ◽  
Solute Content

Water loss, sucrose gain and the variation in concentration of other natural fruit sugars (glucose and fructose) were studied during osmotic dehydration of pineapple slices (0.6 mm thick) in sucrose solution (60 % w/w) at three temperatures (30, 40 and 50ºC). As temperature increased from 30 to 50ºC, the apparent moisture and sucrose diffusivities (Dw and Ds) increased 3.8 and 2.8 times, respectively; therefore, the dehydration efficiency index (Dw/Ds) increased with temperature. The loss of glucose and fructose increased with temperature too. It was found that the solute content was a linear function of the moisture content and this relation was independent of the temperature during the first 600 minutes of dehydration.

scholarly journals Optimization of the osmotic dehydration of ginger

2019 ◽  
Vol 49 (10) ◽  
Author(s):  
Leonardo Pereira de Siqueira ◽  
Leonie Asfora Sarubbo ◽  
Neide Kazue Sakugawa Shinohara ◽  
Marcela Sarmento Valencia ◽  
Neila Mello Santos Cortez ◽  
...  
Keyword(s):  
Immersion Time ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
Efficiency Index ◽  
Moisture Loss ◽  
Experimental Planning ◽  
Osmotic Solution ◽  
C 50 ◽  
Favorable Conditions ◽  
Sanitary Conditions

ABSTRACT: The present research aimed to optimize the process of osmotic dehydration (OD) of ginger with hypertonic sucrose solution employing response surface methodology. A 23 experimental planning was carried out and 17 experimental assays were performed based on three independent variables (temperature, concentration of the osmotic solution and immersion time) and three dependent variables (moisture loss (ML), solids gain (SG) and dehydration efficiency index (DEI)). The selected assay conditions exhibited the preferred DEI value (the highest ML and lower SG), which were considered in the optimization. Assay 16 demonstrated to be the most favorable conditions for the osmotic dehydration of ginger (DEI =1.61) at 40 40 °C, 50 °Brix and 90 minutes of immersion time. Assay 1 performed at 34 °C, 44 °Brix and 120 minutes of immersion time also displayed desirable response (DEI =1.45). Thus, these two assays were evaluated for the presence of thermal-tolerant coliforms: Bacillus cereus and Salmonella sp.. The analyses presented values below the acceptable limits, which assured high quality hygienic and sanitary conditions of the product.

scholarly journals 592 Water Flux from Lettuce Plants at Reduced Atmospheric Pressure

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 499A-499
Author(s):  
Kenneth A. Corey ◽  
Phil A. Fowler ◽  
Raymond M. Wheeler
Keyword(s):  
Relative Humidity ◽  
Plant Growth ◽  
Vapor Pressure ◽  
Water Loss ◽  
Atmospheric Pressure ◽  
Ambient Pressure ◽  
High Vacuum ◽  
Thermal Control ◽  
Plant Responses ◽  
Reduced Pressure

Reduced atmospheric pressures may be used to minimize mass and engineering requirements for plant growth habitats used in some extraterrestrial applications. A chamber with high vacuum capability and thermal control at Kennedy Space Center was used to measure water loss of lettuce plants at reduced atmospheric pressures. A test stand with three, high-pressure sodium vapor lamps was used to determine short-term plant responses to reduced pressure. Initial experiments with lettuce showed that a pressure of 10 kPa (≈0.1 atm) resulted in a 6.1-fold increase in the rate of water loss compared to water loss at ambient pressure. However, due to low relative humidity, plants wilted after 30 minutes exposure to 10 kPa. A follow-up experiment in which relative humidity was controlled between 70% and 85%, demonstrated that water loss was directly proportional to the vapor pressure gradient, regardless of atmospheric pressure in the pressure range of 10 to 101 kPa. However, the response was curvilinear, suggesting effects on the pathway resistance. Results indicate that plant growth at atmospheric pressures of 5 to 10 kPa should be achievable. Further work will necessitate better relative humidity control and carbon dioxide control in order to separate vapor pressure deficit effects from diffusion effects.

Long Term Osmotic Dehydration Processes of Orange Peel at Atmospheric Pressure and by Applying a Vacuum Pulse

2001 ◽  
Vol 7 (6) ◽  
pp. 511-520 ◽  
Author(s):  
M. Cháfer ◽  
C. González-Martínez ◽  
M. D. Ortolá ◽  
A. Chiralt
Keyword(s):  
Atmospheric Pressure ◽  
Structural Changes ◽  
Osmotic Dehydration ◽  
Orange Peel ◽  
Normal Pressure ◽  
Volume Density ◽  
Solution Viscosity ◽  
Solute Content ◽  
Osmotic Solution ◽  
Dehydration Processes

Osmotic dehydration is a useful tool to obtain orange peel products with good sensory acceptance and stability. Osmodehydration of orange peel has been carried out in different osmotic solutions (65 Brix sucrose, 55 Brix glucose and concentrated rectified grape must) at 40 and 50 C for different durations (0–10 days), at atmospheric pressure and by applying a vacuum pulse at the beginning of the process. Changes in sample composition (water and soluble solid contents), weight, volume, density and porosity were analyzed. In all conditions, samples reached the same sample solute content as the osmotic solution at about 24 h of treatment, and the concentration rate was faster when vacuum pulse was applied. Mass transfer behavior showed that impregnation of the peel pores occurred to a great extent, not only when applying vacuum pulse, but also in treatments at normal pressure, due to the capillary effects and pressure gradients generated in the tissue associated with structural changes. Impregnation contributed to compositional changes and weight development of the sample. The greater the osmotic solution viscosity, the lower the impregnation level at equilibrium, which was always promoted by vacuum pulse.

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