Influence of Osmotic Pre-treatment on Convective Drying Kinetics of Figs

2013 ◽  
Vol 9 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Juliana M. Silva ◽  
Muriel G. Cantu ◽  
Vera Rodrigues ◽  
Marcio A. Mazutti
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Osmotic Dehydration ◽  
Sucrose Concentration ◽  
Drying Kinetics ◽  
Soluble Solids ◽  
Convective Drying ◽  
Final Time ◽  
Osmotic Treatment ◽  
Kinetics Of

AbstractThis work evaluated the effects of osmotic dehydration on convective drying kinetics of figs. It used the experimental design methodology to evaluate the influence of sucrose concentration, temperature and time on the amount of total soluble solids (TSS) and moisture content of the figs. After the osmotic dehydration, it evaluated the convective drying kinetics at temperatures from 55 to 75°C. A mathematical model was employed to fit the experimental data. From the experimental data of the osmotic dehydration, it was seen that the moisture content of the figs after the treatment was closely related to the amount of TSS of the figs. Low moisture content and high TSS content were obtained for a narrow range of independent variables comprised between 55–60°C, 55–63 wt% and 260–280 min for temperature, sucrose concentration and exposure time, respectively. In the convective drying kinetics of the figs, there were no verified significant differences in the final time of drying of non-treated and osmotically dehydrated figs. However, the shrinkage was considerably reduced in the osmotically treated figs. The use of osmotic treatment enables the obtainment of figs softer than the simple use of convective drying without changing the final time of drying.

scholarly journals Drying Kinetics of Noni Seeds

2019 ◽  
Vol 11 (5) ◽  
pp. 250 ◽  
Author(s):  
Wellytton Darci Quequeto ◽  
Osvaldo Resende ◽  
Patrícia Cardoso Silva ◽  
Fábio Adriano Santos e Silva ◽  
Lígia Campos de Moura Silva
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Moisture Content ◽  
Mathematical Models ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Information Criterion ◽  
Drying Kinetics ◽  
Kinetics Of

Noni seeds have been used for years as an important medicinal source, with wide use in the pharmaceutical and food industry. Drying is a fundamental process in the post-harvest stages, where it enables the safe storage of the product. Therefore, the present study aimed to fit different mathematical models to experimental data of drying kinetics of noni seeds, determine the effective diffusion coefficient and obtain the activation energy for the process during drying under different conditions of air temperature. The experiment used noni seeds with initial moisture content of 0.46 (decimal, d.b.) and dehydrated up to equilibrium moisture content. Drying was conducted under different controlled conditions of temperature, 40; 50; 60; 70 and 80 ºC and relative humidity, 24.4; 16.0; 9.9; 5.7 and 3.3%, respectively. Eleven mathematical models were fitted to the experimental data. The parameters to evaluate the fitting of the mathematical models were mean relative error (P), mean estimated error (SE), coefficient of determination (R2), Chi-square test (c2), Akaike Information Criterion (AIC) and Schwarz’s Bayesian Information Criterion (BIC). Considering the fitting criteria, the model Two Terms was selected to describe the drying kinetics of noni seeds. Effective diffusion coefficient ranged from 8.70 to 23.71 × 10-10 m2 s-1 and its relationship with drying temperature can be described by the Arrhenius equation. The activation energy for noni seeds drying was 24.20 kJ mol-1 for the studied temperature range.

scholarly journals Mathematical modeling of pequi pulp drying and effective diffusivity determination

2017 ◽  
Vol 21 (7) ◽  
pp. 493-498 ◽  
Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Air Speed ◽  
Drying Curves ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

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 WEST INDIAN CHERRY: INFLUENCE OF OSMOTIC PRETREATMENT

2011 ◽  
Vol 29 (2) ◽  
Author(s):  
MIRTES APARECIDA DA CONCEIÇÃO SILVA ◽  
JEFFERSON LUIZ GOMES CÔRREA ◽  
ZAQUEL ERNESTO DA SILVA
Keyword(s):  
Effective Mass ◽  
Sucrose Solution ◽  
Osmotic Dehydration ◽  
West Indian ◽  
Mass Diffusion ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Malpighia Emarginata ◽  
Order Of Magnitude ◽  
Kinetics Of

The purpose of this work was to study the influence of osmotic pretreatment on the convective drying kinetics of the West Indian cherry (Malpighia emarginata DC). Osmotic dehydration was performed with a 65ºBrix sucrose solution at room temperature, having the fruits immersed for 4 or 12 hours, using a 1:10 proportion of fruit:solution (w:w). After the osmotic dehydration, the fruits were convectively-dried at 50ºC on a tray dryer. The convection drying was modeled based on Fick’s second law, while the effective mass diffusion (Def) was determined using Levenberg-Marquardt’s minimization algorithm by means of the paradigm of inverse methods. The values of effective mass diffusion coefficients observed were in the same order of magnitude as those reported in the literature. The condition that promoted the highest value of diffusivity was convective drying preceded by 4 hours of osmotic dehydration. This condition was also the one with the best fit agreement of the tested model.

scholarly journals Convective drying kinetics of osmotically pretreated papaya cubes

2020 ◽  
Vol 24 (3) ◽  
pp. 200-208 ◽  
Author(s):  
João P. de L. Ferreira ◽  
Deise S. de Castro ◽  
Inacia dos S. Moreira ◽  
Wilton P. da Silva ◽  
Rossana M. F. de Figueirêdo ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Air Temperature ◽  
Removal Rate ◽  
Osmotic Dehydration ◽  
Effective Diffusion ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Transfer Coefficients ◽  
Thin Layer Drying ◽  
Kinetics Of

ABSTRACT This study assessed the fitting of mathematical models to the convective drying kinetics of osmotically pre-dehydrated papaya cubes. Papaya cubes were subjected to osmotic dehydration in sucrose solutions at 40 and 50 ºBrix, at temperatures of 50 and 60 ºC, followed by complementary convective drying in forced air circulation oven under three temperatures (50, 60 and 70 °C) and constant air velocity of 1.0 m s-1. Ten thin-layer drying mathematical models were fitted to the experimental data. The increase in air temperature and the decrease in osmotic solution concentration resulted in increased water removal rate. Based on the statistical indices, the Two Terms model was the one that best described the drying kinetics of the samples for all evaluated conditions. The effective diffusion coefficients increased with the elevation of air temperature, ranging from 1.766 x 10-10 to 3.910 x 10-6 m2 s-1, whereas the convective mass transfer coefficients ranged from 3.910 x 10-7 to 1.201 x 10-6 m s-1 with Biot number from 0.001 to 12.500.

Drying kinetics of processed natural coffee with high moisture content

2017 ◽  
Vol 12 (3) ◽  
pp. 400 ◽  
Author(s):  
Valdiney Cambuy Siqueira ◽  
Flávio Meira Borém ◽  
Guilherme Euripedes Alves ◽  
Eder Pedroza Isquierdo ◽  
Afonso Celso Ferreira Pinto ◽  
...  
Keyword(s):  
Moisture Content ◽  
Drying Kinetics ◽  
High Moisture Content ◽  
High Moisture ◽  
Kinetics Of

Objetivou-se, com o presente trabalho, propor um novo método de processamento e secagem, assim como avaliar o comportamento dos grãos submetidos a este processo, por meio da taxa de redução de água e do ajuste de diferentes modelos matemáticos aos dados experimentais da secagem. Os frutos colhidos no estágio maduro foram divididos em três lotes. O primeiro foi seco continuamente à temperatura de 40±1 °C. O segundo consiste na secagem do café natural até os teores de água de 0,56±0,02, 0,41±0,02, 0,28±0,02 e 0,20±0,02 decimal (base seca, b.s.), seguido de beneficiamento e secagem contínua nas temperaturas de 35±1 ºC e 40±1 ºC. O terceiro lote correspondeu à secagem contínua do café descascado e desmucilado na temperatura de 40±1 °C. Em todos os lotes, a secagem foi encerrada quando os grãos atingiram o teor de água de 0,12±0,05 (b.s.). Aos dados experimentais da secagem foram ajustados dez modelos matemáticos utilizados para representação da secagem dos produtos agrícolas. Além da representação da cinética de secagem foi avaliada a taxa de redução de água dos grãos. Conclui-se que a taxa de redução de água é maior para a temperatura de secagem de 40±1 °C, especialmente para maiores teores de água. O tempo total de secagem do café beneficiado com alto teor de água é expressivamente reduzido, quando comparado ao tempo de secagem completa do café natural. O modelo de Midilli descreve satisfatoriamente a cinética de secagem do café beneficiado.

Research of drying kinetics of prepared wheat flour

2021 ◽  
Vol 9 (16) ◽  
pp. 212-220
Author(s):  
Liubomyr Khomichak ◽  
◽  
Inha Kuznietsova ◽  
Svetlana Vysotska ◽  
Sergiy Tkachenko ◽  
...  
Keyword(s):  
Moisture Content ◽  
Wheat Flour ◽  
Raw Materials ◽  
Control Sample ◽  
Raw Material ◽  
Convective Drying ◽  
Kinetic Dependence ◽  
Vital Functions ◽  
Kinetic Coefficients ◽  
Kinetics Of

Introduction. Processing of grain raw material with influence on starch or albumens by application of heat treatment creates the variety of functional properties of a product and is perspective in the modern terms vital functions of man. Research methods and methods. The flour obtained from wheat of the Ascanian wheat and from wheat of the soft varieties: Sophia ("sweet wheat"), Blond (soft) and Chornobrova (enriched with micro- and macronutrients) were used in the study. Thermal modification of flour samples was carried out in a convective manner. The control sample for determining the quality indicators is obtained in industrial conditions, extruded wheat flour produced by LLC "AS groups, LTD". Research results. The obtained kinetic dependence shows the gradual loss of moisture standards with different speed which accordingly influences on duration of drying. The moisture content of the drying agent most affects the intensity at the initial stage of the constant drying rate. With an increase in the moisture content of the coolant, the period of constant drying increases and the amount of evaporated moisture increases during this period. With the subsequent removal of moisture from raw materials, the degree of influence of this parameter on the intensity decreases. The nature of the drying curves is the same and the recommended process for obtaining modified flour is the process duration of 300 minutes or 5 hours. It was determined microscopically, that the samples of dried wheat flour have a purpose and are partially destroyed by starch granules and amorphization of biocomposite materials. Based on the data on the kinetics of drying flour samples, the kinetic coefficients and values of the critical moisture content for drying wheat flour were calculated, which is 1.18-1.30 %. It was determined that for the sensorial indicators the obtained samples have indicators characteristic of the varietal characteristics of wheat, from which the flour was taken. In terms of physical and chemical parameters, the modified wheat flour samples are not inferior to the well-known industrial sample of extruded flour. Conclusions. Use of flour, obtained from the wheat with different correlation of amilose and amylopectin, positively influences on a technological process and allows to extend the assortment of modified starch products, and accordingly, food products. Kinetics of the convective drying standards of the flour is investigated. Researches showed that a it is physically modified flour obtained from the different sorts of the soft wheat is not inferior in quality to the extruded wheat flour.

scholarly journals Modelagem matemática da desidratação osmo-convectiva da palma forrageira (Opuntia fícus-indica Mill) utilizando soluções mistas

2015 ◽  
Vol 10 (4) ◽  
pp. 39
Author(s):  
E. T. Silva ◽  
E. C. O. Silva ◽  
R. P. Gusmão ◽  
J. D. Lopes ◽  
T. A. S. Gusmão
Keyword(s):  
Experimental Data ◽  
Water Activity ◽  
Osmotic Dehydration ◽  
Convective Drying ◽  
Human Consumption ◽  
Cactus Pear ◽  
Opuntia Ficus Indica ◽  
Mixed Solutions ◽  
Cut Resistance ◽  
Best Fit

<p>Objetivou-se nesse estudo avaliar a influência de pré-tratamentos osmóticos utilizando secagem convectiva complementar no processo de perda de água, ganho de sólidos e nos parâmetros de qualidade (cor, atividade de água e textura) de cladódios de palma forrageira. O Cladódio foi submetido à desidratação osmótica utilizando soluções mistas contendo 5% de NaCl e concentrações de sacarose de 50 e 60 °Brix, em diferentes proporções palma/solução (1:1, 1:4 e 1:10) a 40°C. Posteriormente foi realizada secagem convectiva a 50 e 60 °C. Foram utilizados, para ajuste aos dados experimentais da secagem, os modelos matemáticos de Page, Henderson &amp; Pabis, Cavancanti Mata, Exponencial de Dois Termos e Midilli. O cladódio de palma <em>in natura</em> e desidratado foi caracterizado quanto aos parâmetros de cor, atividade de água e textura. O aumento da perda de massa foi proporcional ao aumento da proporção cladódio/solução utilizada na desidratação osmótica e o ganho de sólidos foi maior para a concentração de 50 °Brix. O modelo matemático de Midilli foi o que melhor se ajustou aos dados experimentais. Os parâmetros de cor, atividade de água e textura foram modificados pelas condições de desidratação osmótica e de secagem as quais o cladódio de palma foi submetido. O cladódio desidratado a 50 °C apresentou melhor preservação da cor, maior resistência ao corte e menor atividade de água.<strong> </strong></p><p><strong> </strong></p><p align="center"><strong><em>Mathematical modeling of osmo-convective dehydration of the cactus pear (Opuntia ficus-indica Mill) using mixed solutions</em></strong><strong><em></em></strong></p><p><strong>Abstract</strong><strong>: </strong>The objective of this study was to evaluate the influence of osmotic pre-treatments with complementary convective drying in the water loss process and solids gain of cactus pear cladodes, to obtain palm for human consumption. The cladode was subjected to osmotic dehydration using mixed solutions containing 5% NaCl and sugar concentrations of 50 and 60 °Brix in different proportions palm/solution (1:1, 1:4 and 1:10) at 40 °C. Subsequently convective drying was performed at 50 and 60 °C. Were used to fit to the experimental data of drying, the mathematical models for Page, Henderson &amp; Pabis, Cavancanti Mata, Exponential of Two Terms and Midilli. The spineless cactus in natura and dehydrated was characterized as the parameters: color, water activity and texture. The study noted that the increased of weight mass was proportional to the increased of proportion cladode/solution used in osmotic dehydration and the solids gain was higher for concentration of 50 °Brix. The Midilli mathematical model was the best fit to the experimental data. The parameters of color, water activity and texture were modified by the conditions of osmotic dehydration and drying which spineless cactus cladodes was submitted. The cactus cladode dehydrated at 50 °C presented better preservation of the color, increased cut resistance and lowest water activity.</p>

scholarly journals Effect of Thermophysical Properties on Coupled Heat and Mass Transfer in Porous Material during Forced Convective Drying

2014 ◽  
Vol 6 ◽  
pp. 830387 ◽  
Author(s):  
Wei Cai ◽  
Lexian Zhu ◽  
Shilin Dong ◽  
Guozhen Xie ◽  
Junming Li
Keyword(s):  
Porous Medium ◽  
Diffusion Coefficient ◽  
Temperature Distribution ◽  
Moisture Content ◽  
Initial Conditions ◽  
Positive Impact ◽  
Soret Effect ◽  
Convective Drying ◽  
Large Temperature ◽  
Kinetics Of

The convective drying kinetics of porous medium was investigated numerically. A mathematical model for forced convective drying was established to estimate the evolution of moisture content and temperature inside multilayered porous medium. The set of coupled partial differential equations with the specified boundary and initial conditions were solved numerically using a MATLAB code. An experimental setup of convective drying had been constructed and validated the theoretical model. The temperature and moisture content of the potato samples were dynamically measured and recorded during the drying process. Results indicate that thermal diffusion coefficient has significant positive impact on temperature distribution and mass diffusion coefficient might directly affect the moisture content distribution. Soret effect has a significant impact on heat flux and temperature distribution in the presence of large temperature gradient.

scholarly journals Drying kinetics of baru flours as function of temperature

2018 ◽  
Vol 22 (10) ◽  
pp. 713-719 ◽  
Author(s):  
Douglas R. Reis ◽  
Fabrício B. Brum ◽  
Eduardo J. O. Soares ◽  
Jessiana R. Magalhães ◽  
Fabrício S. Silva ◽  
...  
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Food Industry ◽  
Nutritional Value ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Statistical Parameters ◽  
Noticeable Effect ◽  
Different Temperatures ◽  
Kinetics Of

ABSTRACT Several types of seeds have been initially used in the food industry due to the great potential that vegetable proteins have. Baru is a fruit commonly found in the Cerrado biome, having a high nutritional value. This paper aimed to determine and analyze the drying kinetics of whole and defatted baru almond flours at different temperatures. The flour resulting from almond milling was defatted using petroleum ether. The drying processes were performed at temperatures of 40, 50 and 60 ºC. The mathematical models of Page, Henderson and Pabis, Midilli & Kucuk, Thompson and Approximation of Diffusion were fitted to the experimental data. The results showed a noticeable effect of air temperature on the drying kinetics of whole and defatted baru almond flours. According to the statistical parameters of analysis, the models Midilli & Kucuk and Page were the ones with the best fits to the experimental data. The effective diffusivity values found ranged from 8.02 × 10–10 to 19.90 × 10–10 m2 s-1 and for the activation energy were 22.39 and 39.37 KJ mol-1 for whole and defatted almonds, respectively.

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