Mathematical modeling and thermodynamic properties in the drying of citron watermelon seeds

ABSTRACT Citron watermelon is an agricultural product of excellent economic potential. Its seeds are widely used for oil extraction, serving as an energy source, showing nutritional characteristics that make them a suitable product to be studied. Thus, the objective was to characterize citron watermelon seeds regarding their physicochemical composition, in addition to determining drying kinetics, fitting mathematical models to the data, and determining the effective diffusivity coefficients and thermodynamic properties. The seeds were dried in a convective dryer, varying the drying temperature, with air velocity of 1.0 m s-1. With the increase in drying temperature, there were reductions in moisture content, water activity (aw), ash concentration, total titratable acidity, lipids and reducing sugar. Citron watermelon seeds are rich in lipids and ash, have low sugar concentration and low acidity; their drying kinetics was very well described by the Two Terms and Approximation of Diffusion models, followed by the models of Midilli and Page, which resulted in acceptable fits. Effective diffusivity accompanied the increase in drying temperature, and this behavior was well fitted by an Arrhenius-type equation. Enthalpy and entropy variations were reduced with drying temperature, with increments in Gibbs free energy.

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Impact of citric acid on the drying characteristics of kiwifruit slices

Acta Scientiarum Technology ◽

10.4025/actascitechnol.v42i1.40570 ◽

2020 ◽

Vol 42 ◽

pp. e40570

Author(s):

Ibrahim Doymaz

Keyword(s):

Regression Analysis ◽

Citric Acid ◽

Effective Diffusivity ◽

Type Equation ◽

Moisture Diffusion ◽

Moisture Diffusivity ◽

Diffusivity Coefficient ◽

Drying Time ◽

Drying Temperature ◽

Drying Behaviour

Kiwifruit slices were dried at four different air drying temperatures of 50, 55, 60 and 70ºC and at 2 m s-1 air velocity by using a cabinet dryer in this study. The drying, rehydration and colour characteristics were significantly influenced by pretreatment and drying temperature. The drying time decreased with the increase in drying temperature. The drying rate curves showed that the entire drying process took place in the falling rate period. Five well-known thin-layer models were evaluated for moisture ratios using nonlinear regression analysis. The results of regression analysis indicated that the Midilli & Kucuk model the best to describe the drying behaviour with the lowest c2 and RMSE values, and highest R2 value. The effective moisture diffusivity of the dried kiwifruit slices was calculated with Fick’s diffusion model, in which their values varied from 4.19×10–10 to 6.99×10-10 m2 s-1 over the mentioned temperature range. The dependence of effective diffusivity coefficient on temperature was expressed by an Arrhenius type equation. The calculated values of the activation energy of moisture diffusion were 10.37 and 19.08 kJ mol-1 for citric acid and control samples, respectively

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DRYING KINETICS AND CROSS-LINKING OF SULFUR PREVULCANIZED THICK NATURAL RUBBER LATEX FILM

Rubber Chemistry and Technology ◽

10.5254/rct.13.88908 ◽

2013 ◽

Vol 86 (1) ◽

pp. 57-67 ◽

Cited By ~ 3

Author(s):

Chen Jing ◽

Yang Lei ◽

Zhong Jieping ◽

Li Sidong ◽

Chen Yongjun ◽

...

Keyword(s):

Film Formation ◽

Natural Rubber Latex ◽

Type Equation ◽

Drying Kinetics ◽

Latex Film ◽

Cross Linking ◽

Drying Time ◽

Drying Temperature ◽

Drying Kinetic ◽

Link Density

ABSTRACT In order to investigate drying kinetics of thick natural latex (NR) samples after film formation and the effect on cross-linking of NR latex during the drying process, we employed drying experiment methods, swelling methods, and Fourier transform infrared spectroscopy (FTIR) methods to study the drying and vulcanizing characteristics of NR latex. The results show that the drying temperature and thickness of film have obviously affected drying characteristics. The drying kinetic equation is achieved by mathematic fitting, and the Henderson and Pabis model MR = a exp(−kt) was the best fitted model for the thick NR latex film. The effect of the drying temperature on the drying constant was assessed employing an Arrhenius type equation, which can be expressed as k = 6746 exp[−39.9 × 103/(RT)] (R = 8.314 J mol−1 K−1). The drying constant exponentially decreased with the increasing film thickness. At the beginning of drying, the cross-link density increases rapidly, and up to the maximum value, it would slightly decrease with the prolonged drying time, which the results of FTIR also agree with.

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Convective Hot Air Drying of Chilli Pepper: Process Optimization and Modelling the Drying Kinetics and Quality Attributes of Dried Product

10.21203/rs.3.rs-23883/v1 ◽

2020 ◽

Author(s):

Felix Ajuebor ◽

Oluwafunmilayo Aworanti ◽

Oluseye Agbede ◽

Samuel Agarry ◽

Tinuade Afolabi ◽

...

Keyword(s):

Quality Attributes ◽

Drying Kinetics ◽

Interactive Effects ◽

Optimum Process ◽

Process Conditions ◽

Air Velocity ◽

Chilli Pepper ◽

Drying Time ◽

Drying Temperature ◽

Hot Air

Abstract The objectives of this study were to evaluate the individual and interactive effects of air velocity, relative humidity, drying temperature, and drying time on the cabinet hot air drying and quality attributes of chilli pepper as well as to determine the optimum process conditions using the rotatable central composite design (RCCD) of response surface methodology (RSM). The drying kinetics was also modelled. Four factors with three levels of RCCD were utilized: air velocity (0.5-1.5 m/s), relative velocity (65-75%), drying temperature (50-70 o C), and drying time (180-360 min). Product moisture content (PMC), total plate count (TPC), protein content (PC), and carbohydrate content (CC) were evaluated as the quality attributes (responses). The results showed that the drying experimental data significantly ( p ≤ 0.001) and adequately fitted into second-order quadratic regression models with (>0.95) to describe and predict all the responses. Drying time and drying temperature are the most significant drying conditions that exerted more pronounced linear and interactive effects on the dried chilli pepper quality attributes. The predicted optimum process conditions for the production of dried chilli pepper with minimum PMC and TPC as well as maximum PC and CC were obtained to be: drying temperature, 69.98 o C, air velocity, 1.46 m/s, relative humidity, 66.57%, and drying time, 359.86 min. Four empirical models (Page, Newton, Logarithmic, and Henderson and Pabis) were fitted to the drying data and the Page model with (>0.95) best fitted the data to describe the drying kinetics.

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Effect of Ethyl Oleate Pretreatment on Drying of Ginger: Characteristics and Mathematical Modelling

Journal of Chemistry ◽

10.1155/2013/890384 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

A. Waheed Deshmukh ◽

Mahesh N. Varma ◽

Chang Kyoo Yoo ◽

Kailas L. Wasewar

Keyword(s):

Agricultural Sector ◽

Ethyl Oleate ◽

Effective Diffusivity ◽

Air Velocity ◽

Temperature Dependent ◽

Drying Temperature ◽

Thin Layer Drying ◽

Drying Models ◽

Drying Behaviour ◽

Kinetics Of

Ginger is of high value and export oriented commodity crop, which plays an important role in agricultural sector. Proper drying techniques are required to capitalize this crop. In the present study, the effect of chemical pretreatment of alkaline ethyl oleate on drying behaviour of ginger was investigated and compared with untreated ginger at selected temperatures of 45, 55, and 65°C at a constant air velocity of 1.8 m/s. The drying rate curves showed that drying occurred in falling rate period and the drying times of pretreated ginger were shorter than those of untreated ginger. Thin-layer drying models such as Newton, Page, Modified Page, Henderson and Pabis, and Wang and Singh were evaluated based on statistical criteria. The Page model was found to be a better model for describing the drying kinetics of the ginger. The rehydration capacity of pretreated sample was more than that of untreated sample and increased with drying temperature. The transport of water during drying was temperature dependent and described by Fick’s equation. The effective diffusivity varied from to m2/s and to m2/s with drying temperature for untreated and pretreated ginger slices, respectively.

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Drying Kinetics of Maize Cob Using Mathematical Modelling

Journal of Agricultural Engineering ◽

10.52151/jae2021581.1733 ◽

2021 ◽

Vol 58 (1) ◽

pp. 40-49

Author(s):

Pankaj Kumar ◽

Dhritiman Saha

Keyword(s):

Moisture Content ◽

Initial Moisture Content ◽

Effective Diffusivity ◽

Drying Kinetics ◽

Drying Time ◽

Drying Temperature ◽

Page Model ◽

Maize Cob ◽

Kinetics Of ◽

Maize Cobs

Maize cobs (with husk and without husk) with initial moisture content of 78.38 % and 62.39 % (d.b.), respectively, were dried up to 20 % moisture content (d.b.) at three temperatures (45°C, 55°C and 65°C). Moisture ratios (MR) were calculated from moisture loss data and fitted to six (Newton’s, Page, Thompson, Modified Page, Henderson and Pabis, and Wang and Singh) drying mathematical models. Coefficient of determination (R2) and root mean square error (RMSE) were used for comparison of the models. From the analyses, Modified Page model showed the best fit to the experimental data with R2 varying from 0.9924 to 0.9968 for maize cob with husk and 0.9994 to 9989 for cobs without husk at given drying temperatures. The Modified Page model was found to be a superior model representing the drying kinetics of maize cob with and without husk at drying temperatures of 45, 55, and 65°C. The increase in drying temperature caused a reduction in drying time, and the drying took place in the falling rate period. Maize cobs with husk took more time for drying as compared to that without husk at the same temperature. The values of effective diffusivity lied between 1.079×10-8 m2.s-1 and 4.239×10-8 m2.s-1 for maize cob with husk, and between 1.194×10-8 m2.s-1 and 5.230×10-8 m2.s-1 for maize cob without husk. Effective diffusivity increased with an increase in drying temperature and was higher for maize cob without husk than that of with husk

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Effect of Ultrasound on Henna Leaves Drying and Extraction of Lawsone: Experimental and Modeling Study

Energies ◽

10.3390/en14051329 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1329

Author(s):

Said Bennaceur ◽

Abdelaziz Berreghioua ◽

Lyes Bennamoun ◽

Antonio Mulet ◽

Belkacem Draoui ◽

...

Keyword(s):

Effective Diffusion ◽

Type Equation ◽

Extraction Yield ◽

Lawsonia Inermis ◽

Air Velocity ◽

Drying Time ◽

Drying Temperature ◽

Ultrasound Application ◽

Degradation Reaction ◽

Kinetics Of

The effect of drying temperature and the application of ultrasound on drying kinetics of Lawsonia inermis (henna) leaves and the extraction of lawsone from the dried samples was addressed. Indeed, henna leaves were dried with and without the application of ultrasound (21.7 kHz, 30.8 kW/m3) at 40, 50 and 60 °C with a constant air velocity (1 m/s). As expected, both the increase of temperature and the application of ultrasound decreased the drying time and increased the rate of extraction of the lawsone. The values of the effective diffusion coefficients obtained were used to quantify this influence showing the value increases with higher drying temperature and the application of ultrasound. Moreover, the influence of temperature was quantified by the estimation of the activation energy from an Arrhenius-type equation (46.25 kJ/mol in the case of drying without ultrasound application and 44.06 kJ/mol in the case of ultrasonically-assisted drying). Regarding the influence of studied variables on lawsone extraction yield, the higher is the temperature, the lower is the yield, probably linked with lawsone degradation reaction due to thermal treatment. On the contrary, the application of ultrasound improved the extraction yield mainly at the lower drying temperature tested of 40 °C.

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Modeling drying kinetics of Jacaranda mimosifolia seeds with variable effective diffusivity via diffusion model

Biosystems Engineering ◽

10.1016/j.biosystemseng.2021.03.008 ◽

2021 ◽

Vol 205 ◽

pp. 234-245

Author(s):

Marcos P. Felizardo ◽

Giovanni R.F. Merlo ◽

Gustavo D. Maia

Keyword(s):

Diffusion Model ◽

Effective Diffusivity ◽

Drying Kinetics ◽

Kinetics Of ◽

Jacaranda Mimosifolia

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Drying of sliced tomato ( Lycopersicon esculentum L.) by a novel halogen dryer: Effects of drying temperature on physical properties, drying kinetics, and energy consumption

Journal of Food Process Engineering ◽

10.1111/jfpe.13624 ◽

2020 ◽

Author(s):

Asaad Rehman Al‐Hilphy ◽

Mohsen Gavahian ◽

Francisco J. Barba ◽

José M. Lorenzo ◽

Zainab Musaddaq Al‐Shalah ◽

...

Keyword(s):

Energy Consumption ◽

Lycopersicon Esculentum ◽

Physical Properties ◽

Drying Kinetics ◽

Drying Temperature

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Mathematical modeling and determination of thermodynamic properties of jabuticaba peel during the drying process

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v20n6p576-580 ◽

2016 ◽

Vol 20 (6) ◽

pp. 576-580 ◽

Cited By ~ 8

Author(s):

Cristian F. Costa ◽

Paulo C. Corrêa ◽

Jaime D. B. Vanegas ◽

Fernanda M. Baptestini ◽

Renata C. Campos ◽

...

Keyword(s):

Experimental Data ◽

Thermodynamic Properties ◽

Drying Process ◽

Drying Temperature ◽

Air Temperatures ◽

Nutritional Qualities ◽

Forced Air ◽

Air Circulation ◽

Best Fit

ABSTRACT Jabuticaba is a fruit native of Brazil and, besides containing many nutritional qualities, it also has a good field for use in products such as flour for cakes and biscuits, juice, liqueur, jelly and others. This study aimed to model the drying kinetics and determine the thermodynamic properties of jabuticaba peel at different drying air temperatures. Ripe fruits of jabuticaba (Myrciaria jaboticaba) were collected and pulped manually. Drying was carried out in a forced-air circulation oven with a flow of 5.6 m s-1 at temperatures of 40, 50, 60 and 70 °C. Six mathematical models commonly used to represent the drying process of agricultural products were fitted to the experimental data. The Arrhenius model was used to represent the drying constant as a function of temperature. The Midilli model showed the best fit to the experimental data of drying. The drying constant increased with the increment in drying temperature and promoted an activation energy of 37.29 kJ mol-1. Enthalpy and Gibbs free energy decreased with the increase in drying temperature, while entropy decreased and was negative.

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