Modelling and characteristics of thin layer convective air-drying of thyme (Thymus vulgaris) leaves

Fruit and vegetable dehydration has been extensively studied for the improvement of food preservation. Effects of drying temperature on the drying kinetics of thyme were investigated and a suitable drying model was obtained to describe the drying process. Drying behaviour of thyme leaves at temperatures of 50, 60, 70 and 80°C was determined by using a conventional drying oven, and moisture ratio and drying rates were calculated. Four different thin layer drying models, namely Lewis, Henderson and Pabis, Page, and logarithmic models, were used to fit the experimental moisture ratio data. Three statistical parameters: coefficient of determination (R<sup>2</sup>), chi-square (χ<sup>2</sup>) and root mean square error (RMSE) were used to compare the goodness of fit of the drying models. Logarithmic model and Page model give the best description of the drying process kinetics of thyme leaves by comparing the experimental values and predicted values.

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Kinetika Pengeringan Lapisan Tipis Daun Jati Belanda (Thin Layer Drying Kinetics of Guazuma Ulmifolia Leaves)

Jurnal Keteknikan Pertanian ◽

10.19028/jtep.08.2.53-62 ◽

2021 ◽

Vol 8 (2) ◽

pp. 53-62

Author(s):

Hendri Syah ◽

Armansyah Halomoan Tambunan ◽

Edy Hartulistiyoso ◽

Lamhot Parulian Manalu

Keyword(s):

Mass Transfer ◽

Thin Layer ◽

Moisture Diffusivity ◽

Drying Kinetics ◽

Coefficient Of Determination ◽

Convective Mass Transfer ◽

Thin Layer Drying ◽

Drying Models ◽

Guazuma Ulmifolia ◽

Kinetics Of

The objectives of this study were to determine a suitable thin layer drying model to describe the drying kinetics of Guazuma ulmifolia leaves and determine the mass transfer parameters of Guazuma ulmifolia leaves. The drying of Guazuma ulmifolia leaves was conducted in a laboratory scale dryer with various temperature (40oC, 50oC, and 60oC) and relative humidity (30%, 40%, 50% and 60%). Five drying models, namely, Newton, Henderson and Pabis, Page, Midilli-Kucuk, and Verma et al. were fitted to the drying data. The drying curve of guazuma leaves did not show a constant drying period during the drying period. The models suitability were compared base on coefficient of determination (R2), root square mean errors (RSME), and reduced mean square of deviation (X2). It was found that, among the models evaluated, the Midilli and Kucuk model is the best to describe the drying kinetics of Guazuma ulmifolia leaves. The effective moisture diffusivity was found to be in the range of 10-13 – 10-12 m2/s and the convective mass transfer coefficient was in the range of 10-9 – 10-10 m/s. The activation energy value was found to be 89.21 kJ/mol.

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Dehydration Kinetics of Cassava, Yam and Potato Slices Using a Refractance WindowTM Dryer

FUOYE Journal of Engineering and Technology ◽

10.46792/fuoyejet.v3i2.258 ◽

2018 ◽

Vol 3 (2) ◽

Author(s):

Akinjide A Akinola ◽

Stanley N. Ezeorah

Keyword(s):

Moisture Content ◽

Thin Layer ◽

Coefficient Of Determination ◽

Plastic Film ◽

Thin Layer Drying ◽

Drying Models ◽

Thin Layer Drying Models ◽

Drying Curves ◽

Kinetics Of ◽

Potato Slices

This study aims to investigate the drying characteristics of cassava, yam, and potato slices using a laboratory scale batch Refractance Window™ (RW) dryer. The experimental dryer was constructed by modifying a laboratory water bath. The bath was covered with a transparent Polyethylene terephthalate (PET) plastic film held in-place with angled edges. The cassava, yam, and potato slices were dried on the Refractance WindowTM dryer, and the variation of the moisture content of the slices during the drying process was measured. The water temperature beneath the plastic film was maintained at 60oC. The dehydration data were fitted to thin-layer drying models. Regression analysis suggested that the Haghi and Ghanadzadeh model best describes the dehydration behaviour for the 3 mm thick slices for the cassava, yam, and potato tubers. The coefficient of determination (R2) values of 0.999, 0.998, and 0.998 for the cassava, yam, and potato slices respectively were reported in all the models studied. The drying curves, the drying rate curves, and the Krischer curves, from the experimental drying data, was plotted. Observations indicate that the cassava, yams, and potatoes slices dried to below 0.11 g water/g-solid moisture content in about 150 min. This study was performed to facilitate the understanding of the design, modelling, and operations of a continuously operating RW dryer. Keywords: Refractance Window Drying, Thin Layer Drying Models, Yams, Cassava, Potatoes.

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Modeling of thin layer drying characteristics of “Xiem” banana peel cultivated at U Minh district, Ca Mau province, Vietnam

Food Research ◽

10.26656/fr.2017.5(5).180 ◽

2021 ◽

Vol 5 (5) ◽

pp. 244-249

Author(s):

N.V. Tai ◽

M.N. Linh ◽

N.M. Thuy

Keyword(s):

Activation Energy ◽

Thin Layer ◽

Goodness Of Fit ◽

Effective Diffusivity ◽

Coefficient Of Determination ◽

Banana Peel ◽

Drying Rate ◽

Drying Process ◽

Drying Temperature ◽

Thin Layer Drying

In Vietnam, banana peels have been discarded as waste which is a potential source of raw material for food and other bioprocessing industries. Drying the peel offers opportunities for value addition into novel products, thus reducing waste from the fruit processing operations. This study presented the mathematical models of the thin-layer drying behaviour of banana peels using three air temperatures (60oC, 70oC and 80oC). The effect of drying temperature on the reduction of moisture content and drying rate of the banana peel was evaluated. A total of eight commonly drying models were used for choosing the best fitness model for describing the oven drying process. The effective moisture diffusivity and activation energy were calculated using Fick’s diffusion equation. The obtained results showed that increasing drying temperature accelerate the drying process, as well as, increasing drying rate and effective diffusivity. The goodness of fit tests base on the criterion indicated that the Page model gave the best fit to experimental results. The effective diffusivity varied from 2.29×10-8 – 3.25×10-8 m 2 /s. Effective diffusivity was satisfactorily by an Arrhenius relationship with activation energy within the 60-80°C temperature range. The obtained activation energy was 16.98 kJ/mol with a high coefficient of determination (R2 = 0.903).

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NONLINEAR MODELS FOR INFRARED DRYING OF MINT

Latin American Applied Research - An international journal ◽

10.52292/j.laar.2019.280 ◽

2019 ◽

Vol 49 (1) ◽

pp. 19-24

Author(s):

E. K. BASAR ◽

N. HEYBELI ◽

M. Z. FIRAT ◽

C. ERTEKIN*

Keyword(s):

Goodness Of Fit ◽

Nonlinear Models ◽

Information Criterion ◽

Coefficient Of Determination ◽

Drying Process ◽

Infrared Drying ◽

Thin Layer Drying ◽

Drying Models ◽

Thin Layer Drying Models ◽

Logistic Functions

In this paper, 105 different semitheoretical and empirical thin layer drying models were used for describing the drying process of the mint leaves. Comparisons of the overall goodness of fit were based on Coefficient of Determination (R2), Root Mean Square Error (RMSE), Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). It was concluded that five parameter Cedergreen-Ritz-Streibig modified log-logistic functions with alpha equal to 0.25 (CRS5C) model describe the infrared drying process of the mint leaves. Furthermore, temperature effect was investigated by using reduction test. Finally, it was found that the effect is statistically significant and the model with separate trends fits these data better.

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Model Pengeringan Lapisan Tipis Rebung Bambu “Tabah” (Gigantochloa nigrociliata KURZ)

Rona Teknik Pertanian ◽

10.17969/rtp.v9i1.4408 ◽

2016 ◽

Vol 9 (1) ◽

pp. 62-73

Author(s):

Gede Arda ◽

P.K. Diah Kencana ◽

IBP. Gunadnya ◽

Ni Luh Yulianti

Keyword(s):

Thin Layer ◽

Coefficient Of Determination ◽

Drying Process ◽

Page Model ◽

Air Temperatures ◽

Bamboo Shoots ◽

Thin Layer Drying ◽

Drying Models ◽

Preliminary Study ◽

Drying Model

Abstrak. Rebung bambu tabah (Gigantochloa nigrociliata KURZ) merupakan produk khas daerah Pupuan, Tabanan, Bali yang mempunyai potensi untuk dikembangkan sebagai produk yang bernilai ekonomis. Kajian awal proses pengeringan rebung untuk meningkatkan umur simpan rebung bambu Tabah dilakukan pada penelitian ini. Kurva laju pengeringan rebung bambu Tabah memberikan informasi penting untuk proses pengeringan. Oleh karena itu, tujuan penelitian ini adalah mempelajari karakteristik laju pengeringan rebung bambu Tabah melalui aplikasi model pengeringan lapisan tipis. Rebung bambu Tabah yang dibelah menjadi dua dan empat bagian dikeringkan pada suhu 50oC, 60oC, dan 70oC. Perubahan kadar air setiap saat kemudian dimodelkan dengan model Newton dan Page. Kesesuaian model yang digunakan dievaluasi dengan menentukan nilai koefisien determinasi (r2) dan RMSE dari model. Hasil menunjukkan bahwa model Page lebih baik digunakan untuk memodelkan pengeringan rebung bambu Tabah pada semua perlakuan. Model Newton menunjukkan ketidaksesuaian yang sangat tinggi pada suhu 50oC namun kesesuaiannya meningkat pada suhu yang lain. Thin Layer Drying Model of Bamboo Shoots “Tabah” (Gigantochloa nigrociliata KURZ) Abstract. Bamboo shoots Tabah (Gigantochloa nigrociliata KURZ) is a unique product of Pupuan District, Tabanan, Bali which is potent to be developed as highly value product. Preliminary study of the bamboo shoots drying to enhance its storage life was conducted in this research. Bamboo shoots Tabah’s drying rate curve give an important information for its drying process. Therefore, the aim of this research was to study the characteristics of bamboo shoots Tabah drying by applying thin layer drying models. Bamboo shoots split into two and four pieces were dried under drying air temperatures 50oC, 60oC, and 70oC. Instantaneous moisture content of the shoots are modeled by Newton and Page model. The goodness of the models were evaluated by determining its coefficient of determination (r2) and RMSE. The results showed that Page model was better to model the bamboo shoots Tabah drying process on all drying treatments. The Newton Model indicated the worst fit on drying air temperature 50oC while showed better fit on other temperatures.

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A Mathematical Model for Thin-Layer Drying of Litchi Pulp

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.192.51 ◽

2012 ◽

Vol 192 ◽

pp. 51-56

Author(s):

Zhi Qiang Guan ◽

Xiu Zhi Wang ◽

Min Li ◽

Xiao Qiang Jiang

Keyword(s):

Experimental Data ◽

Thin Layer ◽

Heat Pump ◽

Moisture Ratio ◽

Drying Time ◽

Page Model ◽

Thin Layer Drying ◽

Drying Models ◽

Heat Pump Drying ◽

Predicted Values

A drying experiment of litchi pulp was done with a self-built heat-pump drying system. A few commonly-used thin-layer drying models for foods were linearized and fitted with the drying experimental data to select a relatively optimal model of depicting the relationship between moisture ratio and drying time of the heat-pump drying of litchi pulp. It was found that the Page model is relatively optimal. The multivariate linear regression approach was employed to solve for the parameters of the Page model based on experimental data and an experimental verification was conducted; the verification results show that the predicted values of the Page model have a good fitness with the measured values and thus the Page model can predict more accurately the moisture ratio and drying rate of litchi pulp in a heat-pump drying process.

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Thin Layer Drying Process of Some Leafy Vegetables under Open Sun

Food Science and Technology International ◽

10.1177/1082013207075953 ◽

2007 ◽

Vol 13 (1) ◽

pp. 35-40 ◽

Cited By ~ 36

Author(s):

O. P. Sobukola ◽

O. U. Dairo ◽

L. O. Sanni ◽

A. V. Odunewu ◽

B. O. Fafiolu

Keyword(s):

Thin Layer ◽

Effective Diffusivity ◽

Thin Layers ◽

Leafy Vegetables ◽

Drying Process ◽

Chi Square ◽

Thin Layer Drying ◽

Rate Period ◽

Drying Models ◽

Drying Curves

Open sun drying experiments in thin layers of crain-crain (CC), fever (FV) and bitter (BT) leaves grown in Abeokuta, Nigeria were conducted. The drying process took place in the falling rate period and no constant rate period was observed from the drying curves. Eight thin layer mathematical drying models were compared using the multiple determination coefficients (R2), reduced chi-square (χ2) and root mean square error (RMSE) between the observed and predicted moisture ratios. Accordingly, Midilli et al. model satisfactorily described the drying curves of the three leaves with R2 of 0.9980, χ2 of 2.0×10-4 and RMSE of 1.09×10-2 for CC leaves; R2 of 0.9999, χ2 of 2×10-6 and RMSE of 1.11×10-3 for FV leaves; and R2 of 0.9998, χ2 of 1.9×10-5 and RMSE of 3.3×10-3 for BT leaves. The effective diffusivity was found to be 52.91×10-10, 48.72×10-10 and 43.42×10-10 m2/s for CC, BT and FV leaves, respectively.

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Drying kinetics of dill leaves in a convective dryer

International Agrophysics ◽

10.2478/v10247-012-0066-y ◽

2013 ◽

Vol 27 (1) ◽

pp. 39-47 ◽

Cited By ~ 18

Author(s):

A. Motevali ◽

S. Younji ◽

R. Amiri Chayjan ◽

N. Aghilinategh ◽

A. Banakar

Keyword(s):

Thin Layer ◽

Back Propagation ◽

Moisture Diffusivity ◽

Moisture Ratio ◽

Coefficient Of Determination ◽

Feed Forward ◽

Threshold Functions ◽

Feed Forward Back Propagation ◽

Thin Layer Drying ◽

Drying Behavior

Abstract Thin layer drying characteristics of dill leaves under fixed, semi-fluidized, and fluidized bed conditions were studied at air temperatures of 30, 40, 50, and 60°C. In order to find a suitable drying curve, 12 thin layer-drying models were fitted to the experimental data of the moisture ratio. Among the applied mathematical models, the Midilli et al. model was the best for drying behavior prediction in thin layer drying of dill leaves. To obtain the optimum network for drying of dill leaves, various numbers of multilayer feed-forward neural networks were made and tested with different numbers of hidden layers and neurons. The best neural network feed-forward back-propagation topology for the prediction of drying of dill leaves (moisture ratio and drying rate) was the 3-45-2 structure with the training algorithm trainlm and threshold functions logsig and purelin. The coefficient of determination for this topology for training, validation, and testing patterns was 0.9998, 0.9981, and 0.9990, respectively. Effective moisture diffusivity of dill leaves during the drying process in different bed types was found to be in the range from 7.10 10-12 to 1.62 10-10 m2 s-1. Also, the values of activation energy were determined to be between 75.435 and 80.118 kJ mol-1

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Drying Process Modelling for Heavy Clay Products Using a New Thin Layer Drying Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.371.323 ◽

2013 ◽

Vol 371 ◽

pp. 323-327

Author(s):

Miloš Vasić ◽

Zagorka Radojević

Keyword(s):

Thin Layer ◽

Mathematical Models ◽

Process Modelling ◽

Experimental Investigations ◽

Drying Process ◽

Thin Layer Drying ◽

Heavy Clay ◽

Drying Models ◽

Drying Model ◽

Thin Layer Drying Models

Drying results, determined on samples made of masonry clay from the locality "Banatski Karlovac", are presented in this study. Experimental investigations were carried out in a laboratory recirculation dryer in which drying parameters (humidity, temperature, and velocity) could be programmed, controlled and monitored during drying process. Several mathematical models were used for drying process modelling. New semi-theoretical thin layer drying model, for heavy clay products, was developed and presented in this study. It represents a modification of Page's and logarithm's thin layer drying models. Results presented in this study have shown that new thin layer drying model describes and correlates the best experimentally determined drying process.

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