scholarly journals Determination of moisture diffusivity and activation energy on fixed bed drying of red pepper (Capsicum annum) on convective solar drying

2021 ◽  
Vol 4 (2) ◽  
pp. 110-116
Author(s):  
Siti Asmaniyah Mardiyani ◽  
Sumardi Hadi Sumarlan ◽  
Bambang Dwi Argo ◽  
Amin Setyo Leksono
Keyword(s):  
Activation Energy ◽  
Fixed Bed ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Red Pepper ◽  
Convective Drying ◽  
Energy Calculation ◽  
Solar Drying ◽  
Effective Moisture ◽  
Drying Behavior

Moisture diffusivity and activation energy are two important variables in a drying process to understand a certain product's drying behavior. This study aimed to determine the value of effective moisture diffusivity and the activation energy of red pepper in a conventional forced convective drying based on electricity (conventional convective drying/CCD) and forced convective drying based on solar energy (convective solar drying/CSD). The value of effective moisture diffusivity was determined using the equation, which refers to Fick’s second law. The Arrhenius equation determines the activation energy value as a model of the relationship of inverse temperature and the normal logarithmic value of effective moisture diffusivity. The results showed that the values of effective moisture diffusivity of CCD 70 °C were the highest. The regression analysis between the drying layers (X), and effective moisture diffusivity (Y) showed a polynomial pattern with a coefficient determination R2 value of 0.85 (CCD 70 °C), 0.81 (CCD 60 °C), 0.88 (CCD 50 °C), and 0.48 (CSD). (R2) The higher moisture diffusivity values in CCD indicated that the drying systems are more stable than CSD. The drying activation energy calculation showed that the value of CCD's activation energy was 36.36 kJ/mol.K, while the value of CSD's activation energy was 31.28 kJ/mol.K. Those results were consistent with the results of the previous studies.

Experimental Investigation to Evaluate the Effective Moisture Diffusivity and Activation Energy of Cassava (Manihot Esculenta) under Convective Drying

2021 ◽  
Author(s):  
Pathiwat Waramit ◽  
Bundit Krittakom ◽  
Ratinun Luampon
Keyword(s):  
Activation Energy ◽  
Type Equation ◽  
Moisture Diffusivity ◽  
Experimental Results ◽  
Effective Moisture Diffusivity ◽  
Convective Drying ◽  
Air Velocity ◽  
Drying Time ◽  
Hot Air ◽  
Effective Moisture

Investigation of effective moisture diffusivity (Deff) and activation energy (Ea) of cassava were conducted under convective drying at temperature and velocity of 60, 70 and 80 °C, and 1.0, 1.5 and 2.0 m/s, respectively. In the experiment, cassava was sliced into 3 mm-thickness and dried under given conditions until mass was saturated. Deff and Ea were described by Fick’s second law and Arrhenius-type equation, respectively. The experimental results indicated that the increase in Deff was significantly affected by increasing the hot air temperature and velocity. The slope method was used to calculate average Deff, and results were found to range from 3.83 × 10–9 – 9.86 × 10–9 m2/s. The Ea was found to decrease with an increase in hot air velocity, ranging from 21.23– 24.92 kJ/mol. Additionally, Moisture content (Mw) and Drying rate (DR) were also used to describe the drying kinetics. From the experimental results, Mw and DR decreased with an increase in drying time. DR increased with an increase in temperature and velocity causing Mw to rapidly decrease and drying time to reduce. The highest DR was found to be 0.55 gwater/min at temperature of 80 °C and velocity of 2.0 m/s.

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.

Comparative Study on Drying of Selected Marine Products: Bombay Duck (Herpodon nehereus) and Prawn (Penaeus indicus)

2011 ◽  
Vol 7 (4) ◽  
Author(s):  
Ganesh Lotanrao Visavale ◽  
Parag P Sutar ◽  
Bhaskar Narayan Thorat
Keyword(s):  
Freeze Drying ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Hot Air ◽  
Effective Moisture ◽  
Page Model ◽  
Drying Behavior ◽  
Marine Products ◽  
Drying Rates ◽  
Bombay Duck

A study on drying of two types of fish, viz., Bombay duck and Prawn, using the open sun, a solar cabinet, hot air and freeze drying was carried out. The fish were dried to 5–6% moisture content. The drying rates were calculated and drying data were fitted to the Page model, and on the basis of R2 and RMSE values it was found that the Page model describes satisfactorily the drying behavior of Bombay duck and Prawn. Also, effective moisture diffusivity values were calculated during fish drying by different methods. The values of the average effective moisture diffusivity of Bombay duck and Prawn were in the range of 1.01 × 10-9 to 1.51 × 10-9 m2 s-1and 0.21 × 10-9 to 0.31 × 10-9 m2 s-1, respectively. Freeze drying was found to provide the best quality of dehydrated product, which was as expected. Solar cabinet drying was found to be a low-energy intensive process compared to freeze and hot air drying, resulting in a dehydrated product with acceptable quality.

scholarly journals Convective drying of squash (Cucurbita moschata): Influence of temperature and air velocity on effective moisture diffusivity, carotenoid content and total phenols

DYNA ◽  
2017 ◽  
Vol 84 (202) ◽  
pp. 112-119 ◽  
Author(s):  
Diana Carolina Potosí-Calvache ◽  
Pedro Vanegas-Mahecha ◽  
Hugo Alexander Martinez Correa
Keyword(s):  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Convective Drying ◽  
Carotenoid Content ◽  
Cucurbita Moschata ◽  
Total Phenols ◽  
Air Velocity ◽  
Influence Of Temperature ◽  
Effective Moisture

Se estudia la influencia de la temperatura y la velocidad del aire en el secado convectivo de zapallo (Cucúrbita moschata- UNAPAL Abanico 75), por medio de la cinética de secado y los cambios en el contenido de compuestos fenólicos y carotenos totales. Se empleó la metodología de superficie de respuesta para optimizar las condiciones de operación en el secado de pulpa de zapallo. Los factores estudiados fueron, temperatura de secado (45 – 65 °C) y velocidad de aire (4 y 7 m.s-1). Las condiciones óptimas de secado de pulpa de zapallo fueron; 55 °C y 7m. s-1, para la temperatura y velocidad de aire respectivamente. El tiempo de secado fue 390 min aproximadamente. La harina obtenida presento humedad 6.34 ± 0.10 % (bh), carotenoides totales; 141.5 ± 1.32 mg/100 g de muestra, fenoles totales; 72.9 ± 2.2 mg /100 g de muestra.

scholarly journals THE EFFECT OF CONVECTIVE FIXED BED DRYING BASED ON A SOLAR COLLECTOR AND PHOTOVOLTAIC (CSD) TO THE QUALITY ATRIBUTES OF RED PEPPER COMPARED WITH CONVENTIONAL CONVECTIVE FIXED BED DRYING (CCD)

2019 ◽  
Vol 7 (1) ◽  
pp. 24-33
Author(s):  
Siti Asmaniyah Mardiyani ◽  
Sumardi Hadi Sumarlan ◽  
Bambang Dwi Argo ◽  
Amin Setyo Leksono
Keyword(s):  
Ascorbic Acid ◽  
Solar Collector ◽  
Fixed Bed ◽  
Quality Attributes ◽  
Red Pepper ◽  
Convective Drying ◽  
Solar Drying ◽  
Rehydration Ratio ◽  
Drying System

The effect of conventional convective drying (CCD) and convective solar drying (CSD) based on a solar collector and photovoltaic on the quality of dried red pepper was researched. The study was aimed to determine the effect of five drying system (CCD 50°C, CCD 60°C, CCD 70°C, CSD, and open sun drying) on the quality attributes of dried red pepper. The quality observed were rehydration ratio, ascorbic acid, capsaicin, non-enzymatic browning index, anthocyanin, and carotenoids. The results of the study confirmed that the drying system significantly affected the quality attributes of dried red pepper except for anthocyanin.  The CSD had a satisfactory result, shown by some attributes  (carotenoids, ascorbic acid, and ratio) which were not statistically different from the quality of dried red pepper gained from CCD 50°C.

scholarly journals Modelling the Drying Characteristics and Kinetics of Hot Air-Drying of Unblanched Whole Red Pepper and Blanched Bitter Leaf Slices

2017 ◽  
Vol 5 (1) ◽  
pp. 24
Author(s):  
Samuel Enahoro Agarry
Keyword(s):  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Red Pepper ◽  
Coefficient Of Determination ◽  
Drying Time ◽  
Drying Characteristics ◽  
Hot Air ◽  
Effective Moisture ◽  
Drying Curves ◽  
Kinetics Of

The objective of this study was to investigate the drying characteristics and kinetics of red pepper and bitter leaf under the influence of different drying temperatures. The drying experiments were carried out at dry bulb temperature of 35, 45, 55 and 75oC, respectively in an oven dryer. The results showed that as drying temperature increased, drying rate also increased and the drying time decreased. It was observed that un-sliced red pepper and sliced bitter leaf would dry within 2.5-12 h and 1.67-7 h, respectively at temperature ranging from 75 to 35oC. The drying of red pepper and bitter leaf was both in the constant and falling rate period. Four semi-empirical mathematical drying models (Newton, Page, Henderson and Pabis, and Logarithmic models) were fitted to the experimental drying curves. The models were compared using the coefficient of determination (R^2) and the root mean square error (RMSE). The Page model has shown a better fit to the experimental drying data of red pepper and bitter leaf, respectively as relatively compared to other tested models. Moisture transport during drying was described by the application of Fick’s diffusion model and the effective moisture diffusivity was estimated. The value ranges from 15.69 to 84.79 × 10-9 m2/s and 0.294 to 1.263 × 10-9 m2/s for red pepper and bitter leaf, respectively. The Arrhenius-type relationship describes the temperature dependence of effective moisture diffusivity and was determined to be 37.11 kJ/mol and 32.86 kJ/mol for red pepper and bitter leaf, respectively. A correlation between the drying time and the heat transfer area was also developed.

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