Air Drying Kinetics of Pomegranate Seeds

Author(s):  
Sajeev Rattan Sharma ◽  
Sadhna Arora ◽  
Tarsem Chand

The thin layer drying of pretreated wild pomegranate seeds was conducted in a laboratory mechanical dryer at air temperatures of 55, 60 and 65°C. Six different mathematical models were used to predict the drying behavior. Thompson model was adjudged as the best model. The coefficients of this model were found to be correlated best with drying temperatures by using two degree polynomials. The effective diffusivity was determined to be 3.18 x 10-10 to 4.36 x 10-10 m2/s. The activation energy for diffusion was found to be 29.07 kJ /mol. The variation in shrinkage exhibited a linear relationship with moisture content. The rate constants for “a” and “b” parameters of colour were determined and their value was 0.0128 and 0.0136 min-1, respectively.

Author(s):  
Gholamreza Askari ◽  
Atefe Babaki ◽  
Zahra Emamdjomeh

In order to conserve cuminum cyminum L. during long storage periods, the drying kinetics of this seed undergoing microwave-assisted fluidized bed dryer at various microwave output power (300, 600 and 900w), air velocity (10, 15 and 20 m/s) and air temperatures (45, 55 and 65ᵒc) were studied. The main aim of this research is developing a mathematical model of mass transfer to investigate the microwave-assisted fluidized bed drying of cuminum cyminum L. seed. In this paper, we tried to discover a good model to evaluate moisture effective diffusivity (Deff). Keywords: cuminum cyminum L, microwave-assisted drying, mathematical modeling,


2016 ◽  
Vol 12 (2) ◽  
Author(s):  
Hosain Darvishi ◽  
Zanyar Farhudi ◽  
Nasser Behroozi-Khazaei

Abstract Moisture diffusivity (Dem), mass transfer coefficient (hm), activation energy and drying kinetics of the dill leaves were studied and modeled as a function of temperature (40–70 °C) and moisture content (0.20–5.67 kg water/kg dry matter). Results showed that the Dem and hm significantly depend on the temperature and moisture content (p < 0.05). The average of Dem and hm varied between 4.02 × 10–9 to 9.65 × 10–9 m2/s, and 2.38 × 10–7 to 6.33 × 10–7 m/s, respectively. Activation energy showed a significant dependence on the moisture content and estimated as 16.84 kJ/mol for diffusion model and 28.70 kJ/mol for mass transfer model. Out of the six models considered, the logarithmic model showed the best fit to drying behavior of the dill leaves.


2016 ◽  
Vol 369 ◽  
pp. 119-124
Author(s):  
E.M.A. Pereira ◽  
J.V. Silva ◽  
J.P.S. Santos ◽  
T.H.F. Andrade ◽  
A.G. Barbosa de Lima

This work aims to conduct an experimental study of the drying kinetics of castor bean fruits (Ricinuscommunis L., “BRS Energia” variety). Experiments were conducted using an oven at air temperatures 50 and 70°C and air relative humidity values 16.34 and 6.24%, respectively. The castor bean fruits were considered as a triaxial spheroid. The experimental moisture content data as a function of time were fitted to different lumped models (namely Henderson and Pabis, Page, Midilli and two-term exponential models) available in the literature.The values of the effective moisture diffusivity were obtained from the Fick's diffusion model. Results shows that the two-term drying model could adequately describe the thin layer drying behavior of castor bean fruit, and that the effective moisture diffusivity increases with increasing drying air temperature.


2013 ◽  
Vol 17 (3) ◽  
pp. 839-846 ◽  
Author(s):  
Asım Balbay ◽  
Ömer Şahin ◽  
Hakan Ülker

Drying kinetics of Pistachio kernels (PKs) with initial moisture content of 32.4% (w.b) was investigated as a function of drying conditions in a fixed bed drying system. The drying experiments were carried out at different temperatures of drying air (40, 60 and 80?C) and air velocities (0.05, 0.075 and 0.1 m/s). Several experiments were performed in terms of mass of PKs (15g and 30g) using a constant air velocity of 0.075 m/s. The fit quality of models was evaluated using the determination coefficient (R2), sum square error (SSE) and root mean square error (RMSE). Among the selected models, the Midilli et al model was found to be the best models for describing the drying behavior of PKs. The activation energies were calculated as 29.2 kJ/mol and effective diffusivity values were calculated between 1.38 and 4.94x10-10 m2/s depending on air temperatures.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 202
Author(s):  
Ivan Pavkov ◽  
Milivoj Radojčin ◽  
Zoran Stamenković ◽  
Krstan Kešelj ◽  
Urszula Tylewicz ◽  
...  

This study aimed to determine the effects of osmotic dehydration on the kinetics of hot air drying of apricot halves under conditions that were similar to the industrial ones. The osmotic process was performed in a sucrose solution at 40 and 60 °C and concentrations of 50% and 65%. As expected increased temperatures and concentrations of the solution resulted in increased water loss, solid gain and shrinkage. The kinetics of osmotic dehydration were well described by the Peleg model. The effective diffusivity of water 5.50–7.387 × 10−9 m2/s and solute 8.315 × 10−10–1.113 × 10−9 m2/s was calculated for osmotic dehydration. Hot air drying was carried out at 40, 50, and 60 °C with air flow velocities of 1.0 m/s and 1.5 m/s. The drying time shortened with higher temperature and air velocity. The calculated effective diffusion of water was from 3.002 × 10−10 m2/s to 1.970 × 10−9 m2/s. The activation energy was sensitive to selected air temperatures, so greater air velocity resulted in greater activation energy: 46.379–51.514 kJ/mol, and with the osmotic pretreatment, it decreased to 35.216–46.469 kJ/mol. Osmotic dehydration reduced the effective diffusivity of water during the hot air drying process. It also resulted in smaller shrinkage of apricot halves in the hot air drying process.


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

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 &ordm;C 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&rsquo;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 &times; 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.


2008 ◽  
Vol 19 (2) ◽  
pp. 127 ◽  
Author(s):  
S.B. BAKAL ◽  
K.H. GEDAM ◽  
G.P. SHARMA

In developed countries, more than 50% potatoes are consumed as processed products. As drying is the vital phenomenon in processing, it is necessary to investigate the drying characteristics and its kinetics. In this experimental study, drying kinetics of Potato in two different shape of cuboidal & cylindrical with three aspect ratio was investigated as a function of drying conditions. Experiments were conducted using air temperatures of 50, 60 and 70 ºC, at velocity of 7 ms-1. The experimental moisture data were fitted to Page and simple models available in the literature, and a good agreement was observed. The Page model gave better fit than simple model. In the ranges covered, the values of the effective moisture diffusivity, Deff were obtained between 2.278 × 10-9 to 3.314 × 10-8 m2s-1 from the Fick's diffusion model. Using Deff, the value of activation energy (Ea) was determined assuming the Arrhenius-type temperature relationship.


Author(s):  
Kivaandra Dayaa Rao Ramarao ◽  
Zuliana Razali ◽  
Chandran Somasundram

Drying kinetics of Malaysian Moringa oleifera leaves was investigated using a convective-air dryer. The drying parameters were: temperature (40, 50, 60, 70 °C), air velocity (1.3 m s<sup>–1</sup>, 1.7 m s<sup>–1</sup>). The drying process took place in the falling rate period and there was an absence of a constant rate period in this experiment. Six mathematical models (Lewis, Henderson and Pabis, Wang and Singh, Peleg, Page, and logarithmic) were selected for the description of drying characteristics of the leaves. The Wang and Singh model was determined as the best model based on the highest overall coefficient determinant (R<sup>2</sup>) and the lowest overall root mean square error (RMSE). The effective diffusivity (D<sub>eff</sub><sub> </sub>) was also calculated which was in the range of 3.98 × 10<sup>–11</sup> m<sup>2</sup> s<sup>–1</sup> to 1.74 × 10<sup>–10</sup> m<sup>2</sup> s<sup>–1. </sup>An Arrhenius relation was constructed to determine the activation energy for the samples in the convective air dryer. The activation energy for M. oleifera leaves was 39.82 kJ mol<sup>–1</sup> and 33.13 kJ mol<sup>–1</sup> at drying velocities of 1.3 m s<sup>–1</sup> and 1.7 m s<sup>–1</sup>, respectively.


Author(s):  
Douglas R. Reis ◽  
Fabrício B. Brum ◽  
Eduardo J. O. Soares ◽  
Jessiana R. Magalhães ◽  
Fabrício S. Silva ◽  
...  

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.


2011 ◽  
Vol 29 (No. 5) ◽  
pp. 528-538 ◽  
Author(s):  
M. Aghbashlo ◽  
M.H. Kianmehr ◽  
A. Arabhosseini ◽  
T. Nazghelichi

This paper presents a mathematical modelling of the drying process in a semi-industrial continuous band dryer. Carrot slices with the thickness of 5 mm were used for the drying experiments. The experiments were conducted at three air temperatures, 50, 60, and 70&deg;C, three air velocities, 0.5, 1.0, and 1.5 m/s, and three chain linear velocities, 2.38 &times; 10<sup>&ndash;4</sup>, 2.78 &times; 10<sup>&ndash;4</sup>, and 3.33 &times; 10<sup>&ndash;4</sup> m/s with three replications for each treatment. The Lewis, Henderson &amp; Pabis, and Page models were fitted to the experimental data of the moisture ratio against the sample position using non-linear regression analysis by MATLAB computer program. The models were compared based on their coefficients of determination (R<sup>2</sup>), root mean square errors (RMSE), and reduced chi-squares (&chi;<sup>2</sup>) between the experimental and predicted moisture ratios. Consequently, the Page model was selected as the best mathematical model for describing the drying kinetics of the carrot slices. The correlations of the Page model constants k and m with the variables T, U<sub>a</sub> and U<sub>c</sub> were determined. The effective moisture diffusivity varied from 3.21 &times; 10<sup>&ndash;7</sup> to 8.98 &times; 10<sup>&ndash;7 </sup>m<sup>2</sup>/s. The energy of activation varied from 23.02 kJ/mol to 28.1 kJ/mol using Arrhenius type equation. &nbsp;


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