scholarly journals Thin layer drying behaviour of fermented cocoa (Theobroma cacao L.) beans

2018 ◽  
Author(s):  
Saheeda Mujaffar ◽  
Aveena Ramroop ◽  
Darin Sukha
Keyword(s):  
Thin Layer ◽  
Rest Period ◽  
Effective Diffusivity ◽  
Constant Diffusion Coefficient ◽  
Constant Diffusion ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Drying Behaviour ◽  
Drying Curves ◽  
The Impact

To assess the impact of a rest interval and bean turning on the thin-layer drying behavior of fermented cocoa beans, beans of mixed Trinitario varieties were dried in a cabinet oven at three temperatures (40, 50, 60°C) using three drying regimes, namely; continuous drying, intermittent drying (drying for 8h with a rest period of 16h), and intermittent drying with turning of beans.  Moisture content, water activity, pH and colour attributes were measured and sensory evaluation of the cocoa liquor carried out on selected samples.  Drying curves were constructed and drying rate constants (k) and effective diffusivity (Deff) values determined. Keywords: Oven-drying; Fick’s Law; Rate constant; Diffusion coefficient

Thin Layer Drying Process of Some Leafy Vegetables under Open Sun

2007 ◽  
Vol 13 (1) ◽  
pp. 35-40 ◽  
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.

scholarly journals Thin Layer Drying and Modelling of Poultry Litter Briquettes

2019 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Mogomotsi J. Molefe ◽  
Isaac N. Simate
Keyword(s):  
Thin Layer ◽  
Poultry Litter ◽  
Statistical Parameters ◽  
Tunnel Dryer ◽  
Thin Layer Drying ◽  
Chi Squared ◽  
Drying Behavior ◽  
Energy Consuming ◽  
Drying Curves ◽  
Microsoft Office

Drying is an energy consuming process influenced by humidity, air velocity and temperature and is defined as a heat conveyance process wherein the product is heated hence removing moisture. Thin layer drying equations are used to estimate drying times of products and generalizing their drying curves. In this study, mathematical modelling and prediction of drying behavior of poultry litter briquettes (PLB) was investigated through open sun drying (OSD) and solar tunnel drying for moisture content (MC) calculations. A solar tunnel dryer (STD) having a: black painted collector unit, drying unit and black painted vertical bare flat-plate chimney was used. MC results were converted to moisture ratio and fitted into 12 different thin layer drying models, using Microsoft Office Excel, which were compared according to their coefficients of determination to estimate drying curves of PLB. The most accurate model was selected based on three statistical parameters: correlation coefficient (R2), chi-squared (χ2) and Root Mean Square Error (RMSE). Solar insolation of between 220 and 1005 W/m2 resulted in air temperature of up to 64oC at the collector unit, up to 60oC at the drying unit and an ambient temperature of up to 31oC. Exposure of PLB with an average initial MC of 61% (w.b.) to these conditions resulted in a final MC in a range of 0.2-11.2% (w.b.) in 31-55 hours. PLB was dried to similar final weight from whichever drying method although OSD took longer than STD. The Logarithmic model was found to satisfactorily describe the drying curves of PLB with R2 of 9.93E-01-9.99E-01; χ2 of 1.36E-11-6.50E-14; and RMSE of 2.94E-02-1.30E-02.

Thin Layer Drying Characteristics of Eriste: A Dried Cereal Product of Turkey

2008 ◽  
Vol 4 (2) ◽  
Author(s):  
Ayhan Duran ◽  
Ali Adnan Hayaloglu ◽  
Ihsan Karabulut
Keyword(s):  
Thin Layer ◽  
Air Temperature ◽  
Effective Diffusivity ◽  
Sample Thickness ◽  
Suitable Model ◽  
Sample Weight ◽  
Drying Characteristics ◽  
Thin Layer Drying ◽  
Cereal Product ◽  
Drying Curves

Effect of air temperature (50, 60 and 70 °C) and sample thickness (1.0, 1.4 and 1.8 mm) on the thin-layer drying characteristics of eriste was studied by using a tray dryer. The data of sample weight, dry and wet-bulb temperatures were recorded continuously during each experiment and drying curves were obtained. The drying curves were then fitted to five mathematical models available in the literature to estimate a suitable model for drying of eriste. Verma et al. model gave better predictions than other models and satisfactorily described the thin layer characteristics of eriste. The effective diffusivity varied from 1.8 x exp-10 to 1.5 x exp-9 m2 s-1 over the temperature range.

The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

2014 ◽  
Vol 69 (9) ◽  
pp. 1859-1866 ◽  
Author(s):  
Hui-Ling Wang ◽  
Zhao-Hui Yang ◽  
Jing Huang ◽  
Li-Ke Wang ◽  
Cheng-Liu Gou ◽  
...  
Keyword(s):  
Sample Thickness ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying ◽  
Dewatered Sludge ◽  
Drying Curves ◽  
Sludge Drying ◽  
The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

scholarly journals Thin layer drying behavior of Ginkgo biloba L. leaves with respect to Ginkgolide A and Bilobalide content and microbial load

Heliyon ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. e03220
Author(s):  
Vasudha Agnihotri ◽  
Priyanka Adhikari ◽  
Neha Pandey ◽  
Priyanka Sati ◽  
Anita Pandey
Keyword(s):  
Thin Layer ◽  
Ginkgo Biloba ◽  
Microbial Load ◽  
Ginkgolide A ◽  
Thin Layer Drying ◽  
Drying Behavior

scholarly journals Cabya (Piper retrofractum Vahl) fruit under open sun drying: drying behavior and modeling of thin layer drying kinetics

2020 ◽  
Vol 542 ◽  
pp. 012001
Author(s):  
L C Hawa ◽  
Ubaidillah Ubaidillah ◽  
F N Afifah ◽  
N I W Yosika ◽  
A Nurlaily ◽  
...  
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Sun Drying ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Piper Retrofractum

scholarly journals MATHEMATICAL MODELING OF ORANGE SEED DRYING KINETICS

2015 ◽  
Vol 39 (3) ◽  
pp. 291-300 ◽  
Author(s):  
Daniele Penteado Rosa ◽  
Denis Cantú-Lozano ◽  
Guadalupe Luna-Solano ◽  
Tiago Carregari Polachini ◽  
Javier Telis-Romero
Keyword(s):  
Mathematical Modeling ◽  
Thin Layer ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Waste Products ◽  
Juice Processing ◽  
Diffusive Model ◽  
Best Fitting ◽  
Drying Curves ◽  
Kinetics Of

Drying of orange seeds representing waste products from juice processing was studied in the temperatures of 40, 50, 60 and 70 °C and drying velocities of 0.6, 1.0 and 1.4 m/s. Experimental drying kinetics of orange seeds were obtained using a convective air forced dryer. Three thin-layer models: Page model, Lewis model, and the Henderson-Pabis model and the diffusive model were used to predict the drying curves. The Henderson-Pabis and the diffusive models show the best fitting performance and statistical evaluations. Moreover, the temperature dependence on the effective diffusivity followed an Arrhenius relationship, and the activation energies ranging from 16.174 to 16.842 kJ/mol

Influence of Drying Conditions and Mathematical Models on the Thin-Layer Drying of Mushrooms

2014 ◽  
Author(s):  
A. Stegou-Sagia ◽  
D. V. Fragkou
Keyword(s):  
Mass Transfer ◽  
Thin Layer ◽  
Mathematical Models ◽  
Drying Methods ◽  
Suitable Model ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Drying Models ◽  
Drying Rates

In the present research, experimental data from several studies about drying behavior of mushrooms have been selected and used to compare different drying methods and different mathematical thin layer drying models to simulate mushroom drying rates. The white button (Agaricus Bisporus), the oyster (Pleurotus Ostreatus) and the milky mushroom slices have been considered for drying in different dryers such as hot air cabinet dryer and fluidized bed dryer with different slice thicknesses, drying air temperatures (45 °C to 90 °C) and drying air velocities (0.2 m/s to 5 m/s). The entire drying process has taken place in the falling rate period, assuming that internal mass transfer occurred by diffusion in mushroom slices. The study shows that the drying air temperature and the drying air velocity have an effect on the moisture removal from mushrooms and also on the drying time. Mathematical models have been proved to be useful for design and analysis of heat and mass transfer during drying processes. All the drying models considered in this study could adequately represent the thin layer drying behavior of mushrooms. Furthermore, as it is obvious, any type of mushrooms has its own most suitable model.

scholarly journals Thin Layer Drying Kinetics Modelling of Curry Leaves (Murraya koenigii L.) in Cabinet Dryer

2018 ◽  
Vol 2 ◽  
pp. 53-58
Author(s):  
Arjun Ghimire ◽  
Nirajan Magar
Keyword(s):  
Experimental Data ◽  
Thin Layer ◽  
Effective Diffusivity ◽  
Coefficient Of Determination ◽  
Murraya Koenigii ◽  
Small Tree ◽  
Chi Square ◽  
Kinetics Modelling ◽  
Curry Leaves ◽  
Thin Layer Drying

Curry leaves (Murraya koenigii L.) are the sweet smelling leaves of small tree of Rutaceae family native to Southwest Asia. In this study, the effect of temperatures (50, 55 and 60°C) on the drying of curry leaves was investigated. The experimental data were fitted to six thin layer mathematical models (Newton, Page, Handerson and Pabis, logarithmic, two-term exponential and Midilli et al). The models were evaluated in terms of coefficient of determination (R2), chi square (χ2) and root mean square error (RMSE). The Midilli et al model was best fitted to the experimental data of all the models evaluated. The effective diffusivity was calculated using Fick's diffusion equation, and the value varied from 2.07×10-12 m2/s to 2.643×10-12 m2/s. The activation energy and the diffusivity constant were found to be 21.808 kJ/mol and 4.667×10-8 m2/s respectively.

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