Effective moisture diffusivity of garlic cloves undergoing microwave-convective drying

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.

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

Advances in Food Science, Sustainable Agriculture and Agroindustrial Engineering ◽

10.21776/ub.afssaae.2021.004.02.4 ◽

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.

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Characteristics of sunflower seed drying and microwave energy consumption

International Agrophysics ◽

10.2478/v10247-012-0077-8 ◽

2013 ◽

Vol 27 (2) ◽

pp. 127-132 ◽

Cited By ~ 5

Author(s):

H. Darvishi ◽

M. Hadi Khoshtaghaza ◽

G. Najafi ◽

M. Zarein

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Specific Energy ◽

Microwave Power ◽

Specific Energy Consumption ◽

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Convective Drying ◽

Drying Time ◽

Effective Moisture

Abstract The effect of the microwave-convective drying technique on the moisture ratio, drying rate, drying time, effective moisture diffusivity, microwave specific energy consumption, and energy efficiency of sunflower seedswere investigated.Drying took place in the falling rate period. Increasing the microwave power caused a significant decrease in the drying time. The drying data were fitted to four thin-layer drying models. The performance of these models was compared using the coefficient of determination, reduced chi-square and root mean square error between the observed and predicted moisture ratios. The results showed that the Page model was found to satisfactorily describe themicrowave-convective drying curves of sunflower seeds. The effective moisture diffusivity values were estimated from Fick diffusion model and varied from 1.73 10-7 to 4.76 10-7m2s-1. Increasing the microwave power resulted in a considerable increase in drying efficiency and a significant decrease in microwave specific energy consumption. The highest energy efficiency and the lowestmicrowave specific energy consumption were obtained at the microwave power of 300 W.

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Effective Moisture Diffusivity of Onion Slices undergoing Infrared Convective Drying

Biosystems Engineering ◽

10.1016/j.biosystemseng.2005.12.010 ◽

2006 ◽

Vol 93 (3) ◽

pp. 285-291 ◽

Cited By ~ 79

Author(s):

Pankaj B. Pathare ◽

G.P. Sharma

Keyword(s):

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Convective Drying ◽

Effective Moisture

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

Applied Science and Engineering Progress ◽

10.14416/j.asep.2021.10.008 ◽

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.

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Mathematical Modelling the Drying Kinetics of Beetroot Strips during Convective Drying at Different Temperatures

Defence Life Science Journal ◽

10.14429/dlsj.4.12176 ◽

2019 ◽

Vol 4 (2) ◽

pp. 140-149

Author(s):

S. S. Manjunatha ◽

P. S. Raju

Keyword(s):

Air Temperature ◽

Large Scale ◽

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Convective Drying ◽

Effective Moisture ◽

Kinetic Coefficients ◽

Thin Layer Drying ◽

Drying Kinetic ◽

Drying Behaviour

The thin layer drying of beetroot strips was evaluated at drying temperatures from 60 °C to 90 °C using convective dryer at inlet air velocity of 1.0 m/s. The different drying models were tested to evaluate the drying characteristics of beetroot strips. The investigations showed that Page’s and modified Page’s equations were satisfactorily describing the drying behaviour of beetroot strips during convective drying with appreciable high correlation coefficient (0.9971<r<0.9990) with low error values. The effective moisture diffusivity was increased from 3.563 x 10-10 m2/s to 8.038 x 10-10 m2/s with increase in drying temperature. The temperature dependency of effective moisture diffusivity was described by Arrhenius equation and activation energy for moisture diffusivity was 30.08 KJ/mol. The drying kinetic coefficients were significantly (p<0.05) affected by drying air temperature. The exponents of models were decreased linearly with drying air temperature during drying of beetroot strips. The equilibrium moisture content was markedly affected by drying air temperature and it decreased linearly with drying air temperature. The results were very useful in standardisation and optimisation of drying process of beetroot strips in large scale commercial production.

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Optimization and Prediction of the Drying and Quality of Turnip Slices by Convective-Infrared Dryer under Various Pretreatments by RSM and ANFIS Methods

Foods ◽

10.3390/foods10020284 ◽

2021 ◽

Vol 10 (2) ◽

pp. 284

Author(s):

Ebrahim Taghinezhad ◽

Mohammad Kaveh ◽

Antoni Szumny

Keyword(s):

Energy Efficiency ◽

Color Difference ◽

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Diffusivity Coefficient ◽

Drying Process ◽

Anfis Model ◽

Drying Time ◽

Effective Moisture ◽

Response Variables

Drying can prolong the shelf life of a product by reducing microbial activities while facilitating its transportation and storage by decreasing the product weight and volume. The quality factors of the drying process are among the important issues in the drying of food and agricultural products. In this study, the effects of several independent variables such as the temperature of the drying air (50, 60, and 70 °C) and the thickness of the samples (2, 4, and 6 mm) were studied on the response variables including the quality indices (color difference and shrinkage) and drying factors (drying time, effective moisture diffusivity coefficient, specific energy consumption (SEC), energy efficiency and dryer efficiency) of the turnip slices dried by a hybrid convective-infrared (HCIR) dryer. Before drying, the samples were treated by three pretreatments: microwave (360 W for 2.5 min), ultrasonic (at 30 °C for 10 min) and blanching (at 90 °C for 2 min). The statistical analyses of the data and optimization of the drying process were achieved by the response surface method (RSM) and the response variables were predicted by the adaptive neuro-fuzzy inference system (ANFIS) model. The results indicated that an increase in the dryer temperature and a decline in the thickness of the sample can enhance the evaporation rate of the samples which will decrease the drying time (40–20 min), SEC (from 168.98 to 21.57 MJ/kg), color difference (from 50.59 to 15.38) and shrinkage (from 67.84% to 24.28%) while increasing the effective moisture diffusivity coefficient (from 1.007 × 10−9 to 8.11 × 10−9 m2/s), energy efficiency (from 0.89% to 15.23%) and dryer efficiency (from 2.11% to 21.2%). Compared to ultrasonic and blanching, microwave pretreatment increased the energy and drying efficiency; while the variations in the color and shrinkage were the lowest in the ultrasonic pretreatment. The optimal condition involved the temperature of 70 °C and sample thickness of 2 mm with the desirability above 0.89. The ANFIS model also managed to predict the response variables with R2 > 0.96.

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