scholarly journals THE DETERMINATION OF THE DRYING KINETICS AND ENERGY EFFICIENCY OF RED PEPPER (CAPSICUM ANNUUM L.) USING DIFFERENT DRYING METHODS AND MICROWAVE FINISH DRYING

2020 ◽  
Vol 50 (4) ◽  
pp. 299-307
Author(s):  
Gülşah Çalışkan Koç

The effects of different drying processes namely microwave (MD), freeze (FD), convective (CD), and vacuum drying (VD) and combined drying methods (FD+MD and CD+MD) on drying characteristics, effective moisture diffusivity, and activation energy of red pepper powder and total energy consumption of dryers were investigated. All drying processes took place in combined form of constant and falling rate periods for all drying experiments except for CD and CD+ MD. In order to determine drying kinetics of red pepper pulp (RPP) seven thin layer drying models were fitted to experimental data and Page (MD, FD, CD, VD, CD+MD) and Logarithmic (FD+MD) models which had the highest R2 and lowest χ2 and RMSE were found to satisfactorily describe the drying behavior of RPP. Findings indicated that compared to FD and CD alone, intermitted dried samples had significantly higher Deff (p<0.05). Specific energy consumption values ranged between 3.13 and 664.52 MJ/kg H2O

2016 ◽  
Vol 369 ◽  
pp. 119-124
Author(s):  
E.M.A. Pereira ◽  
J.V. Silva ◽  
J.P.S. Santos ◽  
T.H.F. Andrade ◽  
A.G. Barbosa de Lima

This work aims to conduct an experimental study of the drying kinetics of castor bean fruits (Ricinuscommunis L., “BRS Energia” variety). Experiments were conducted using an oven at air temperatures 50 and 70°C and air relative humidity values 16.34 and 6.24%, respectively. The castor bean fruits were considered as a triaxial spheroid. The experimental moisture content data as a function of time were fitted to different lumped models (namely Henderson and Pabis, Page, Midilli and two-term exponential models) available in the literature.The values of the effective moisture diffusivity were obtained from the Fick's diffusion model. Results shows that the two-term drying model could adequately describe the thin layer drying behavior of castor bean fruit, and that the effective moisture diffusivity increases with increasing drying air temperature.


2021 ◽  
Vol 6 (1) ◽  
pp. 230-242
Author(s):  
Mohammad Kaveh ◽  
Iman Golpour ◽  
João Carlos Gonçalves ◽  
Sara Ghafouri ◽  
Raquel Guiné

Abstract In this study, the drying kinetics, effective moisture diffusivity (D eff), specific energy consumption (SEC), colour, and shrinkage (S b) of pomegranate arils were compared when dried by convective (CV) drying and microwave (MW) drying. The experiments were performed at air temperature of 50, 60, and 70°C and air velocity of 1 m/s for CV drying and 270, 450, and 630 W for MW drying. The results showed that increasing air temperature and MW power increased the D eff. The calculations demonstrated that the maximum D eff for pomegranate arils was obtained for MW drying (630 W). Maximum SEC for pomegranate arils in the CV dryer was 145.12 kWh/kg, whereas in the MW dryer was 35.42 kWh/kg. In MW dryer, the lowest values of colour change and shrinkage were 6.77 and 50.5%, respectively. Comprehensive comparison of the different drying methods (MW and CV) revealed that MW drying had best drying performance for pomegranate arils, considering the drying time, effective moisture diffusion, SEC, colour, and shrinkage.


Author(s):  
Punit Singh ◽  
Prabal Talukdar

Abstract Drying characteristics of elephant foot yam (EFY) are determined at three different air velocities and temperatures using an innovative convective dryer. The performance of the convective dryer is also determined and compared based on four parameters namely total energy consumption, specific energy consumption (SEC), drying and thermal efficiency, working in kinetically controlled regime (KCR), and equilibrium controlled regime (ECR). EFY has excellent medicinal properties and used for the treatment of various diseases; in spite of that, its drying characteristics have not been reported. The entire drying process of the EFY sample can be divided into three stages, and it is observed that around 80% of the moisture is removed in the first stage and only 5% of the moisture is removed in the last stage. The constant drying rate period is absent, and depending on the different slopes, the entire drying rate period comes under three falling rate periods. A correlation of EFY with air velocity and temperature is developed, and the maximum and minimum values of effective moisture diffusivity (EMD) are found to be 2.65 × 10−10 and 7.15 × 10−10 m2/s, respectively.


Author(s):  
Amir Hossein Mirzabe ◽  
◽  
Gholam Reza Chegini ◽  

Sunflower seeds and oil in food and agricultural processing are of great importance. Dried sunflower petals are the most important parts of the sunflower plant that have economic value. Thin-layer drying experiments were performed in a laboratory scale hot-air dryer. The results indicated that with increasing drying temperature and air velocity, time of drying reduces and in most cases, the logarithmic model had the best performance for modeling the drying kinetics. The calculated values of the effective moisture diffusivity varied from 3.16627 ×10-13 to 1.32860 ×10-12 m2 s-1 and the values of the activation energy for air velocities of 0.4 and 0.8 m s-1 were equal to 51.21 and 42.3 kJ mol-1, respectively. Also, to verify whether the production and sale of sunflower petals can be cost effective, economic analysis was done. This analysis showed that drying of sunflower petals is profitable process and the generated revenue can even surpass the revenue from the sale of sunflower seeds.


Author(s):  
Ambe Desmond ◽  
Lobe Elias ◽  
Divine B. Nde

Potatoes (S. tuberosum L) is one of the most important tuber crops in the world. However, its high moisture content and inadequate storage and processing techniques have a negative influence on its quality and availability throughout the year. This work was carried out to optimize the blanching behavior and drying kinetics of potato slices. Fresh potato slices (5, 10 and 15 mm) were blanched at 70, 80 and 90°C for 1, 3 and 5 min following a 3k level full factorial design. The loss in Vitamin C was used as a quality marker for the optimization process. The influence of blanching on the drying behavior of potato slices was carried out at 50, 60 and 70°C. Results showed that blanching parameters had a significant (P < 0.05) effect on vitamin C loss. Optimum blanching conditions were blanching temperature of 80oC, blanching time of 3 min and a slice thickness of 10 mm which gave an average loss in Vitamin C of about 2.6%. Drying data were successfully fitted to three different thin layer drying models. The use of blanching as a pretreatment before the drying of potato is recommended because it reduces the drying time by 30%.


2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.


2014 ◽  
Vol 10 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Hosain Darvishi ◽  
Mohammad Zarein ◽  
Saied Minaei ◽  
Hamid Khafajeh

Abstract The energy and exergy analysis, drying characteristics and mathematical modeling of the thin-layer drying kinetics of white mulberry using microwave drying were investigated. Results indicated that values of exergy efficiency (33.63–57.08%) were higher than energy efficiency (31.85–55.56%). Specific energy consumption increased with increasing microwave power while improvement potential decreased. The specific energy consumption and improvement potential varied from 3.97 to 6.73 MJ/kg water and 0.71 to 2.97 MJ/kg water, respectively. Also, energy efficiency decreased with decrease in moisture content and microwave power level. The best exergy and energy aspect was obtained by drying at 100 W microwave power. Drying took place mainly in warming up, constant rate and falling rate periods. The Page model showed the best fit to experimental drying data. Effective diffusivity increased with decreasing moisture content and increasing microwave power. It varied from 1.06 × 10−8 to 3.45 × 10−8 m2/s, with an energy activation of 3.986 W/g.


2020 ◽  
Vol 259 ◽  
pp. 120963 ◽  
Author(s):  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Ebrahim Taghinezhad ◽  
Vali Rasooli Sharabiani ◽  
Ali Motevali

Author(s):  
L C Hawa ◽  
Ubaidillah Ubaidillah ◽  
F N Afifah ◽  
N I W Yosika ◽  
A Nurlaily ◽  
...  

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