scholarly journals Effective Moisture Diffusivity and Activation Energy of Tannia Cormels: Influence of Temperature, Pre-Treatment and Slice Thickness

2021 ◽  
Vol 40 (1) ◽  
pp. 140-145
Author(s):  
B.O. Oyefeso ◽  
A.O. Raji
Keyword(s):  
Activation Energy ◽  
Cost Effective ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Slice Thickness ◽  
Temperature Dependent ◽  
Effective Moisture ◽  
Xanthosoma Sagittifolium ◽  
Pre Treatment ◽  
Temperature Levels

This study investigated the effects of temperature, pre-treatment and slice thickness on the effective moisture diffusivity and activation energy of tannia (Xanthosoma sagittifolium) cormels. White-fleshed and pink-fleshed varieties of the cormels were used for this study. The effective moisture diffusivity and activation energy of fresh and blanched cormels were determined by drying them at three temperature levels (60, 70 and 80°C) and three slice thicknesses (2, 3 and 4 mm). The effective moisture diffusivity and activation energy of the cormels ranged between 1.47×10−7 and 2.09×10−6 m2s−1 and 49.02 and 63.23 kJmol−1 respectively. The study established that the effective moisture diffusivity and activation energy are drying temperature dependent. The effects of pre-treatment and slice thickness were also found to be significant on the measured parameters. Drying of blanched thin slices of tannia cormels at relatively high temperature levels is recommended for faster and cost-effective drying of the cormels.

Modelling Effective Moisture Diffusivity of Pumpkin (Cucurbita moschata) Slices under Convective Hot Air Drying Condition

2016 ◽  
Vol 12 (5) ◽  
pp. 481-489 ◽  
Author(s):  
Daniel I. Onwude ◽  
Norhashila Hashim ◽  
Rimfiel B. Janius ◽  
Nazmi Nawi ◽  
Khalina Abdan
Keyword(s):  
Activation Energy ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Slice Thickness ◽  
Cucurbita Moschata ◽  
Drying Time ◽  
Hot Air ◽  
Effective Moisture ◽  
Shrinkage Effect ◽  
Increasing Temperature

Abstract This study seeks to investigate the effects of temperature (50, 60, 70 and 80 °C) and material thickness (3, 5 and 7 mm), on the drying characteristics of pumpkin (Cucurbita moschata). Experimental data were used to estimate the effective moisture diffusivities and activation energy of pumpkin by using solutions of Fick’s second law of diffusion or its simplified form. The calculated value of moisture diffusivity with and without shrinkage effect varied from a minimum of 1.942 × 10–8 m2/s to a maximum of 9.196 × 10–8 m2/s, while that of activation energy varied from 5.02158 to 32.14542 kJ/mol with temperature ranging from 50 to 80 °C and slice thickness of 3 to 7 mm at constant air velocity of 1.16 m/s, respectively. The results indicated that with increasing temperature, and reduction of slice thickness, the drying time was reduced by more than 30 %. The effective moisture diffusivity increased with an increase in drying temperature with or without shrinkage effect. An increase in the activation energy was observed due to an increase in the slice thickness of the pumpkin samples.

scholarly journals Optimum Process Parameters and Thermal Properties of Moisture Content Reduction in Water Yam Drying

2021 ◽  
pp. 44-54
Author(s):  
C. Ezedinma Henry ◽  
T. Nwabanne Jospeh ◽  
E. Onu Chijioke ◽  
O. Nwajinka Charles
Keyword(s):  
Activation Energy ◽  
Thermal Properties ◽  
Moisture Content ◽  
Moisture Diffusivity ◽  
Optimum Process ◽  
Slice Thickness ◽  
Hot Air ◽  
Effective Moisture ◽  
Air Dryer ◽  
Water Yam

The determination of optimum process parameters for moisture content reduction in water yam drying using a hot air dryer was the aim of this work. Gravimetric method was used to determine the moisture content. Design of experiment was used with slice thickness, airspeed and temperature as the independent factors. Thermal properties such as effective moisture diffusivity and activation energy were determined. The result showed that slice thickness, airspeed and temperature have significant influence on the moisture content reduction. The effective moisture diffusivity ranged from 2.84 x 10-5 m2/s to 8.10 x 10-5 m2/s. The activation energy was 30.592kJ/mol. Minimum moisture content value of 11.98% was obtained at slice thickness of 2mm, airspeed of 2 m/s and temperature of 70oC. The quadratic model best described the drying process. The hot air dryer can conveniently be used for moisture content reduction in water yam slices which will increase its shelf life.

scholarly journals Effective moisture diffusivity during hot air solar drying of tomato slices

2016 ◽  
Vol 62 (No. 1) ◽  
pp. 15-23 ◽  
Author(s):  
H. Samimi Akhijani ◽  
A. Arabhosseini ◽  
M.H. Kianmehr
Keyword(s):  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Slice Thickness ◽  
Solar Drying ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Chi Square ◽  
Air Drying ◽  
Hot Air ◽  
Effective Moisture

Mathematical modelling and effective moisture diffusivity of tomato (Lycopersicon esculentum) was studied during hot air solar drying. An experimental solar dryer with a swivel collector was used for experiments. The collector followed the solar radiation using a precious sensor. Drying experiments were performed in a thin layer hot air drying at slice thicknesses of 3, 5 and 7 mm and air velocities of 0.5, 1 and 2 m/s. The experimental data were fitted to different mathematical moisture ratio models and the Page model was selected as the best model according to correlation coefficient R<sup>2</sup>, chi-square &chi;<sup>2</sup> and root mean square error (RMSE) parameters. The maximum values of moisture diffusivity was&nbsp;6.98 &times; 10<sup>&ndash;9</sup> m<sup>2</sup>/s at air velocity of 2 m/s and slice thickness of 7 mm while the minimum value of the moisture diffusivity was 1.58 &times; 10<sup>&ndash;9</sup> m<sup>2</sup>/s at air velocity of 0.5 m/s and slice thickness of 3 mm.

scholarly journals DRYING, COLOUR AND REHYDRATION CHARACTERISTICS OF ORANGE SLICES UNDER INFRARED RADIATION HEATING

2022 ◽  
Vol 52 (1) ◽  
pp. 43-48
Author(s):  
Ibrahim Doymaz
Keyword(s):  
Activation Energy ◽  
Statistical Tests ◽  
Type Equation ◽  
Moisture Diffusivity ◽  
Slice Thickness ◽  
Radiation Heating ◽  
Rehydration Ratio ◽  
Effective Moisture ◽  
Drying Conditions ◽  
Kinetics Of

The effect of different infrared (IR) powers on drying of orange slices was investigated in infrared dryer. The orange slices dried at 62, 74 and 88 W infrared powers and constant slice thickness of 6 mm. Results showed that drying, colour and rehydration characteristics of orange slices were greatly influenced by infrared power. The drying data were fitted with five mathematical models available in the literature. Based on the statistical tests applied to make an assessment, the model of Midilli and Kucuk was found to satisfactorily explain drying kinetics of orange slices for all drying conditions. The Fick’s diffusion model was used to calculate the effective moisture diffusivity (Deff) of orange slices. The value of Deff varied from 1.59×10-10 to 2.49×10-10 m2/s. It was found that the effective moisture diffusivities increased with increasing IR power. Activation energy was estimated by a modified Arrhenius type equation as 2.11 kW/kg. As the infrared power increased, the rehydration ratio was found to be reduced. Furthermore, with increase of infrared power, the values of a and DE increased, whereas the values of L, b and C decreased.

Sign in / Sign up

Export Citation Format

Share Document