An experimental study on intensifying osmotic dehydration was carried out ina state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.7A and0.9A) respectively, in which the material is ...An experimental study on intensifying osmotic dehydration was carried out ina state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.7A and0.9A) respectively, in which the material is apple slice of 5mm thickness. The result showed thatacoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was acceleratedwith the increase of cavitating intensity. The water diffusivity coefficients ranged from1.8x10^(-10)m^2·s^(-1) at 0.5A to 2.6x10^(-10)m^2·s^(-1) at 0.9A, and solute diffusivitycoefficients ranged from 3.5x10^(-11) m^2·s^(-1) at 0.5A to 4.6X10^(-11)m^2·s^(-1) at 0.9A. On thebasis of experiments, a mathematical model was established about mass transfer during osmoticdehydration, and the numerical simulation was carried out. The calculated results agree well withexperimental data, and represent the rule of mass transfer during osmotic dehydration intensified byacoustic cavitation.展开更多
Cherry is extremely perishable fruit and it needs to be dried in order to preserve the fruit for later uses. In this work, the influences of different osmotic solution concentrations on water loss （WL）, solid gain ...Cherry is extremely perishable fruit and it needs to be dried in order to preserve the fruit for later uses. In this work, the influences of different osmotic solution concentrations on water loss （WL）, solid gain （SG） and weight reduction （WR） during osmotic dehydration of cherry halves were investigated. These were studied using general factorial design with different sucrose concentrations （40, 55, 70%, w/v） and immersion time （5 hours）. Quadratic regression equations describing the effects of processes on WL, SG and WR were developed. The results revealed that the soaking time and sucrose concentration significantly （P 〈 0.05） influenced most of the quality indices of osmotically-dehydrated cherry halves. It is suggested that the regression equation obtained in this study can be used to find optimum conditions for osmotic dehydration.展开更多
Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration （OD） and/or high electric field （HEF...Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration （OD） and/or high electric field （HEF） application to improve the overall product quality. The aim of this study was to evaluate the effect of osmotic dehydration （50% sucrose） with high electric field strengths of 0.5 and 1.0 kV/cm as pretreatments on the drying kinetics and mass transfer of green apples during convective drying at 65 ~C and microwave drying at 1 W/g. The added value of the OD and HEF on the drying kinetics, and the effective mass transfer coefficients of the subsequent drying methods were investigated through this research. The efficacy of these pre-treatments was assessed and compared using cell disintegration index, product texture and thus bring forth new correlations between these pre-treatments and the cell disintegration index using dielectric spectroscopy and its effect on the product texture.展开更多
An evolutionary nature-inspired Firefly Algorithm (FA) is employed to set the optimal osmotic dehydration parameters in a case study of papaya. In the case, the functional form of the dehydration model is established ...An evolutionary nature-inspired Firefly Algorithm (FA) is employed to set the optimal osmotic dehydration parameters in a case study of papaya. In the case, the functional form of the dehydration model is established via a response surface technique with the resulting optimization formulation being a non-linear goal programming model. For optimization, a computationally efficient, FA-driven method is employed and the resulting solution is shown to be superior to those from previous approaches for determining the osmotic process parameters. The final component of this study provides a computational experimentation performed on the FA to illustrate the relative sensitivity of this evolutionary metaheuristic approach over a range of the two key parameters that most influence its running time-the number of iterations and the number of fireflies. This sensitivity analysis revealed that for intermediate-to-high values of either of these two key parameters, the FA would always determine overall optimal solutions, while lower values of either parameter would generate greater variability in solution quality. Since the running time complexity of the FA is polynomial in the number of fireflies but linear in the number of iterations, this experimentation shows that it is more computationally practical to run the FA using a “reasonably small” number of fireflies together with a relatively larger number of iterations than the converse.展开更多
The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage ＂blah＂ and its earliness. This variety is characterized by its astringent taste and has never been studied extensively...The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage ＂blah＂ and its earliness. This variety is characterized by its astringent taste and has never been studied extensively. An osmotic dehydration treatment is necessary to improve the quality of the final product for maintaining its integrity. Thus, it is a preservation technique that is often used as pretreatment to obtain partially dehydrated fruit. In this experimental study, the cultivar date Lemsi were cut into cubes of 1 cm3 and were immersed in sucrose solutions of 50%, 60% and 70% at 20℃ for 0-240 min. The moisture content, the solute gain, the water loss and the ratio WL/SG are determined and discussed. The results deduced from this work have showed that sugar gain SG, water loss WL and the ratio WL/SG are increased with concentration of osmotic solution. Likewise, the osmotic dehydration treatment need to be followed of a convective drying to ensure the quality of the final product.展开更多
Response surface methodology, according to CCD （central composite design）, was used to determine the optimum processing conditions giving maximum water loss and minimum solid gain during osmotic dehydration of medla...Response surface methodology, according to CCD （central composite design）, was used to determine the optimum processing conditions giving maximum water loss and minimum solid gain during osmotic dehydration of medlars in sucrose solution. The independent variables of osmotic dehydration were temperature （25-65 ℃）, processing time （20-240 min）, sugar concentration （45%-65% w/w） and blanching time （0-180 s）. The optimum conditions were found to be： temperature = 55 ℃, time = 180 min, concentration = 60° Brix and blanching time = 30 s. At this optimum point, water loss, weight reduction and solid gain were found to be 74.12% and 7.136%, respectively.展开更多
Response surface methodology was used to investigate the effect of brine concentration (10% - 20%) solution temperature (35℃ - 55℃), and duration of osmosis (30 - 60 min) with respect to water loss (WL) and salt gai...Response surface methodology was used to investigate the effect of brine concentration (10% - 20%) solution temperature (35℃ - 55℃), and duration of osmosis (30 - 60 min) with respect to water loss (WL) and salt gain (SG). The solu- tion to sample ratio of 5/1 (w/w) was used. The Box-Behnken design of three variables and three levels including seventeen experiments formed by five central points were used for optimizing input parameters. Linear, quadratic and interaction effects of three variables were analyzed with respect to water loss and solid gain. For each response, second order polynomial models were developed using multiple regression analysis. Analysis of variance (ANOVA) was per- formed to check the adequacy and accuracy of the fitted models. The response surfaces and contour maps showing the interaction of process variables were constructed. The optimum operating conditions were: solution temperature 44.89℃, brine concentration of 16.53 per cent and duration of osmosis of 47.59 min. At this optimum point, water loss and salt gain were predicted to be 44.55 per cent and 2.98 percent respectively.展开更多
文摘An experimental study on intensifying osmotic dehydration was carried out ina state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.7A and0.9A) respectively, in which the material is apple slice of 5mm thickness. The result showed thatacoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was acceleratedwith the increase of cavitating intensity. The water diffusivity coefficients ranged from1.8x10^(-10)m^2·s^(-1) at 0.5A to 2.6x10^(-10)m^2·s^(-1) at 0.9A, and solute diffusivitycoefficients ranged from 3.5x10^(-11) m^2·s^(-1) at 0.5A to 4.6X10^(-11)m^2·s^(-1) at 0.9A. On thebasis of experiments, a mathematical model was established about mass transfer during osmoticdehydration, and the numerical simulation was carried out. The calculated results agree well withexperimental data, and represent the rule of mass transfer during osmotic dehydration intensified byacoustic cavitation.
文摘Cherry is extremely perishable fruit and it needs to be dried in order to preserve the fruit for later uses. In this work, the influences of different osmotic solution concentrations on water loss （WL）, solid gain （SG） and weight reduction （WR） during osmotic dehydration of cherry halves were investigated. These were studied using general factorial design with different sucrose concentrations （40, 55, 70%, w/v） and immersion time （5 hours）. Quadratic regression equations describing the effects of processes on WL, SG and WR were developed. The results revealed that the soaking time and sucrose concentration significantly （P 〈 0.05） influenced most of the quality indices of osmotically-dehydrated cherry halves. It is suggested that the regression equation obtained in this study can be used to find optimum conditions for osmotic dehydration.
文摘Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration （OD） and/or high electric field （HEF） application to improve the overall product quality. The aim of this study was to evaluate the effect of osmotic dehydration （50% sucrose） with high electric field strengths of 0.5 and 1.0 kV/cm as pretreatments on the drying kinetics and mass transfer of green apples during convective drying at 65 ~C and microwave drying at 1 W/g. The added value of the OD and HEF on the drying kinetics, and the effective mass transfer coefficients of the subsequent drying methods were investigated through this research. The efficacy of these pre-treatments was assessed and compared using cell disintegration index, product texture and thus bring forth new correlations between these pre-treatments and the cell disintegration index using dielectric spectroscopy and its effect on the product texture.
文摘An evolutionary nature-inspired Firefly Algorithm (FA) is employed to set the optimal osmotic dehydration parameters in a case study of papaya. In the case, the functional form of the dehydration model is established via a response surface technique with the resulting optimization formulation being a non-linear goal programming model. For optimization, a computationally efficient, FA-driven method is employed and the resulting solution is shown to be superior to those from previous approaches for determining the osmotic process parameters. The final component of this study provides a computational experimentation performed on the FA to illustrate the relative sensitivity of this evolutionary metaheuristic approach over a range of the two key parameters that most influence its running time-the number of iterations and the number of fireflies. This sensitivity analysis revealed that for intermediate-to-high values of either of these two key parameters, the FA would always determine overall optimal solutions, while lower values of either parameter would generate greater variability in solution quality. Since the running time complexity of the FA is polynomial in the number of fireflies but linear in the number of iterations, this experimentation shows that it is more computationally practical to run the FA using a “reasonably small” number of fireflies together with a relatively larger number of iterations than the converse.
文摘The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage ＂blah＂ and its earliness. This variety is characterized by its astringent taste and has never been studied extensively. An osmotic dehydration treatment is necessary to improve the quality of the final product for maintaining its integrity. Thus, it is a preservation technique that is often used as pretreatment to obtain partially dehydrated fruit. In this experimental study, the cultivar date Lemsi were cut into cubes of 1 cm3 and were immersed in sucrose solutions of 50%, 60% and 70% at 20℃ for 0-240 min. The moisture content, the solute gain, the water loss and the ratio WL/SG are determined and discussed. The results deduced from this work have showed that sugar gain SG, water loss WL and the ratio WL/SG are increased with concentration of osmotic solution. Likewise, the osmotic dehydration treatment need to be followed of a convective drying to ensure the quality of the final product.
文摘Response surface methodology, according to CCD （central composite design）, was used to determine the optimum processing conditions giving maximum water loss and minimum solid gain during osmotic dehydration of medlars in sucrose solution. The independent variables of osmotic dehydration were temperature （25-65 ℃）, processing time （20-240 min）, sugar concentration （45%-65% w/w） and blanching time （0-180 s）. The optimum conditions were found to be： temperature = 55 ℃, time = 180 min, concentration = 60° Brix and blanching time = 30 s. At this optimum point, water loss, weight reduction and solid gain were found to be 74.12% and 7.136%, respectively.
文摘Response surface methodology was used to investigate the effect of brine concentration (10% - 20%) solution temperature (35℃ - 55℃), and duration of osmosis (30 - 60 min) with respect to water loss (WL) and salt gain (SG). The solu- tion to sample ratio of 5/1 (w/w) was used. The Box-Behnken design of three variables and three levels including seventeen experiments formed by five central points were used for optimizing input parameters. Linear, quadratic and interaction effects of three variables were analyzed with respect to water loss and solid gain. For each response, second order polynomial models were developed using multiple regression analysis. Analysis of variance (ANOVA) was per- formed to check the adequacy and accuracy of the fitted models. The response surfaces and contour maps showing the interaction of process variables were constructed. The optimum operating conditions were: solution temperature 44.89℃, brine concentration of 16.53 per cent and duration of osmosis of 47.59 min. At this optimum point, water loss and salt gain were predicted to be 44.55 per cent and 2.98 percent respectively.
