scholarly journals Influence of intermittent and continuous microwave heating on drying kinetics and wood behavior of Eucalyptus Gomphocephala

2018 ◽  
Author(s):  
Mariam Habouria ◽  
Sahbi Ouertani ◽  
Soufien Azzouz ◽  
Wahbi Jomaa ◽  
Mohamed Taher Elaib ◽  
...  
Keyword(s):  
Power Level ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Continuous Heating ◽  
Average Moisture Content ◽  
Processing Parameter ◽  
Drying Time ◽  
Optimal Processing ◽  
Eucalyptus Wood ◽  
Eucalyptus Gomphocephala

 The aim of this work was to determine the microwave drying kinetics of Eucalyptus Gomphocephala wood  and to investigate the influence of intermittent and continuous heating  processes on the end quality of dreid samples.  The average moisture content evolution and temperature of wood samples under different microwave powers were analyzed in terms of drying time and internal temperature level. Results show that the increase of microwave power level decreses the drying time and increases the internal wood temperature. Based on qualitative observations on the state of dried samples, the intermittent microwave powers intensity process present the optimal processing parameter in microwave drying of  Eucalyptus wood species.Keywords: microwave drying; power; intermittent; continuous; Eucalyptus wood.  

Study of color kinetics of banana (Musa cavendish) under microwave drying by application of image analysis

2020 ◽  
pp. 108201322098133
Author(s):  
Sagar Nagvanshi ◽  
Subbarao Kotra Venkata ◽  
TK Goswami
Keyword(s):  
Microwave Power ◽  
Vision System ◽  
Power Level ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Order Kinetic ◽  
Drying Time ◽  
Volumetric Heating ◽  
Kinetics Of ◽  
Microwave Power Level

Microwave drying works on the volumetric heating concept promoted by electromagnetic radiation at 0.915 or 2.450 GHz. In this study, banana ( Musa Cavendish) was taken as the sample and treated under microwave drying. The effect of two process variables, namely slice thickness (2, 3.5, and 5 mm) and microwave power (180 W, 360 W, and 540 W), were studied on drying kinetics and color kinetics. It was observed that the inverse variation relationship exists between drying time and microwave power level while drying time and slice thickness exhibited a direct variation relationship. A Computer Vision System (CVS) was developed to measure the color values of banana in CIELab space using an algorithm written in MATLAB software. Once the color parameters were obtained, they were fitted in First and Zero-order kinetic models. Both models were found to describe the color values adequately. This study concludes that microwave drying is a promising dehydration technique for banana drying that reduces the significant time of drying. Application of CVS is an excellent approach to measure the surface color of banana.

scholarly journals Drying of Phyla nodiflora Leaves: Antioxidant Activity, Volatile and Phytosterol Content, Energy Consumption, and Quality Studies

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 210 ◽  
Author(s):  
Lisa Yen Wen Chua ◽  
Bee Lin Chua ◽  
Adam Figiel ◽  
Chien Hwa Chong ◽  
Aneta Wojdyło ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Energy Consumption ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Time ◽  
Antioxidant Power ◽  
Vacuum Microwave

Drying is an important process in the preservation of antioxidants in medicinal plants. In this study, leaves of Phyla nodiflora, or commonly known as frog fruit, were dried using convective drying (CD) at 40, 50, and 60 °C; vacuum-microwave drying (VMD) at 6, 9, and 12 W/g; and convective pre-drying followed by vacuum-microwave finish drying (CPD–VMFD) at 50 °C and 9 W/g. Drying kinetics of P. nodiflora leaves was modelled, and the influences of drying methods on the antioxidant activity, total phenolic content, volatile and phytosterol contents, energy consumption, water activity, and color properties were determined. Results showed that drying kinetics was best described by modified Page model. VMD achieved highest drying rate, whereas VMFD considerably reduced the drying time of CD from 240 min to 105 min. CPD–VMFD was the best option to dry P. nodiflora in terms of retaining volatiles and phytosterols, with lower energy consumption than CD. Meanwhile, VMD at 6 W/g produced samples with the highest antioxidant activity with 2,2′-Azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) value of 11.00 and 15.99 µM Trolox/100 g dw, respectively.

Applications of Several Hybrid Drying Methods for a Bioproduct: Effects on Drying Kinetics and Product Colour

2007 ◽  
Vol 2 (5) ◽  
Author(s):  
Kian Jon Chua
Keyword(s):  
Colour Change ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Drying Methods ◽  
Thermal Processes ◽  
Adsorption System ◽  
Drying Time ◽  
Pressure Drops ◽  
Cyclic Pressure ◽  
Drying Techniques

In response to growing expectations for more effective drying of bioproducts with improved quality, this paper presents recent experimental results obtained from employing several hybrid drying techniques. The hybrid drying methods could be classified into thermal and non-thermal processes. The thermal processes included combined convective/infrared and convective-microwave drying while non-thermal process refers to dehydration under conditions of successive pressure drops incorporating an adsorption bed. Potato samples were taken to be the model bioproduct. A comparison of the drying kinetics with product colour degradation showed convective-microwave drying to be an effective method in shortening the drying time to achieve the desired moisture content whilst maintaining acceptable product quality. Bioproduct dehydration in a non-thermal cyclic pressure drop adsorption system resulted in substantial minimisation of the product colour change but at the expense of a longer drying time.

scholarly journals Infrared drying kinetics of blue mussels and physical properties

2019 ◽  
Vol 25 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Azmi Kipcak ◽  
İbrahim Doymaz ◽  
Emek Moroydor-Derun
Keyword(s):  
Blue Mussel ◽  
Power Level ◽  
Colour Change ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Drying Time ◽  
Blue Mussels ◽  
Thin Layer Drying ◽  
Drying Models ◽  
Kinetics Of

As an alternative to fish and beef, blue mussels (Mytilus edulis) can be consumed due to their high protein content. In this study, the drying kinetics and quality changes (cook loss, area shrinkage and colour change) in whole blue mussels were investigated with several infrared power levels between 88?146 W. Various thin-layer drying models were applied to the blue mussel and the Midilli et al., model best fits the experimental data (R2: 0.999150?0.999750, ?2: 0.000104?0.000030, RMSE: 0.008309?0.004797). The effective moisture diffusivity was determined to be between 4.24?10-9 and 1.10?10-8 m2/s. The activation energy was found to be 20.85 kW/kg. The cook loss and area shrinkage increased with increasing power level and drying time. Most cook loss (30%) and area shrinkage (30%) were obtained between 15-23 min and 8-20 min of drying time, respectively. The colour change was slightly affected by the change in infrared power level.

scholarly journals Effect of Microwave Drying on the Drying Characteristics, Color, Microstructure, and Thermal Properties of Trabzon Persimmon

Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 84 ◽  
Author(s):  
Soner Çelen
Keyword(s):  
Energy Consumption ◽  
Color Change ◽  
Power Level ◽  
Effective Diffusion ◽  
Microwave Energy ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Fresh Sample ◽  
Drying Time ◽  
Color Changes

In this study, changes in the drying kinetics, color change, and the energy consumption for microwave energy were investigated for Trabzon persimmon. In addition to that, the microstructure of the persimmon was also investigated by considering its thermal changes. It is important to be aware of the purpose of the drying process for determining the drying system. Results of this research showed that 460 W for 7 mm slice thickness depending on energy consumption, 600 W for 5 mm slice thickness depending on drying time, and 600 W depending on color changes were found as suitable drying processes depending on drying conditions. The effective diffusion values varied between 2.97 × 10−8 m2 s−1 and 4.63 × 10−6 m2 s−1. The activation energy values for 5 mm, 7 mm and 9 mm slice thickness were estimated as 32.82, 18.64, and 12.80 W g−1, respectively. The drying time and energy consumption decreased, whereas drying rate increased with an increase in the microwave energy. The number of pores increased compared to structure of fresh sample, and the pores got to be larger for 5 mm slice thickness as the power level increased. Results showed that the applied microwave energy had an important effect on the heating of the material and the change in the microstructure.

scholarly journals Artificial Neural Network Modeling of Drying Kinetics and Color Changes of Ginkgo Biloba Seeds during Microwave Drying Process

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jun-Wen Bai ◽  
Hong-Wei Xiao ◽  
Hai-Le Ma ◽  
Cun-Shan Zhou
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Ginkgo Biloba ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Drying Process ◽  
Drying Time ◽  
Color Changes ◽  
Rate Period ◽  
Artificial Neural

Ginkgo biloba seeds were dried in microwave drier under different microwave powers (200, 280, 460, and 640 W) to determinate the drying kinetics and color changes during drying process. Drying curves of all samples showed a long constant rate period and falling rate period along with a short heating period. The effective moisture diffusivities were found to be 3.318 × 10−9 to 1.073 × 10−8 m2/s within the range of microwave output levels and activation energy was 4.111 W/g. The L⁎ and b⁎ values of seeds decreased with drying time. However, a⁎ value decreased firstly and then increased with the increase of drying time. Artificial neural network (ANN) modeling was employed to predict the moisture ratio and color parameters (L⁎, a⁎, and b⁎). The ANN model was trained for finite iteration calculation with Levenberg-Marquardt algorithm as the training function and tansig-purelin as the network transfer function. Results showed that the ANN methodology could precisely predict experimental data with high correlation coefficient (0.9056–0.9834) and low mean square error (0.0014–2.2044). In addition, the established ANN models can be used for online prediction of moisture content and color changes of ginkgo biloba seeds during microwave drying process.

scholarly journals Modelling the kinetics of microwave drying of shallot (Allium cepa) slices

2021 ◽  
Vol 1195 (1) ◽  
pp. 012033
Author(s):  
C L Hii ◽  
C Govind ◽  
C L Chiang ◽  
D Mohammad
Keyword(s):  
Thin Layer ◽  
Allium Cepa ◽  
Microwave Power ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Methods ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Rates

Abstract Convective drying is typically used to dry shallot (Allium cepa) commercially. However, a long drying time with a relatively low efficiency has led to the pursuit of new and improved drying methods. Microwave drying was chosen to be used due to its numerous advantages such as improved drying time, high drying efficiency and better product quality. In this research, three microwave power (180 W, 300 W, 450 W) and convective drying at 100°C were used. Results showed that drying kinetics (moisture content and drying rates) decreased the fastest at higher microwave power and the slowest using convective drying. In order to determine the best model to describe the thin-layer drying kinetics, four semi-empirical models were used namely Newton, Page, Logarithmic and Two-term models. Page model was found to be the best in describing the thin-layer microwave drying kinetics. Effective diffusivity values increased with higher microwave power and were found to be in the range of 6.62 × 10−6 m2/s to 3.69 × 10−5 m2/s with convective drying being the lowest (6.62 × 10−6 m2/s) and 450W being the highest (3.69 × 10−5 m2/s). Microwave drying is therefore able to improve drying kinetics compared to convective drying.

scholarly journals LNT microwave-multiphase transport model for the microwave drying of lignite thin layer

2018 ◽  
Author(s):  
Bi An Fu ◽  
Meiqian Chen ◽  
Q. H. Li
Keyword(s):  
Thin Layer ◽  
Transport Model ◽  
Power Level ◽  
Microwave Energy ◽  
Moisture Distribution ◽  
Microwave Drying ◽  
Drying Time ◽  
Multiphase Transport ◽  
Mass Transfer Mechanism ◽  
Simulation Results

The LNT microwave-multiphase transport model has been applied to the microwave drying of lignite thin layer. Microwave energy, temperature and moisture distribution were obtained to gain a comprehensive understanding on the heat and mass transfer mechanism of the drying process. The required drying time of experiments decreased by 50, 63, 67, and 83%, respectively, with the power level rising from 119 to 700 W, while that decreased by 60, 72, 76 and 86%, respectively, for simulation results. The temperature values of the corner and edge of the lignite thin layer were higher than that of the center region, which corresponded to the microwave energy distribution. The moisture ratio profiles, temperature profiles and temperature distribution indicated good agreement between the experimental and simulation results, providing confidence in the modeling approach, which made it possible to obtain the moisture distribution successfully via simulation method.Keywords: microwave; lignite; thin layer.  

Microwave Drying Characteristics and Antidiabetic Properties of Aquilaria subintegra and Aquilaria malaccensis Leaves

2015 ◽  
Vol 1113 ◽  
pp. 352-357 ◽  
Author(s):  
Sxureha Yunus ◽  
Nurul Asyikin Md Zaki ◽  
Ku Halim Ku Hamid
Keyword(s):  
Power Level ◽  
Microwave Treatment ◽  
Microwave Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Aquilaria Malaccensis ◽  
Treatment Of Diabetes ◽  
Drying Curves ◽  
Vitro Analysis

The present study was aimed to investigate the effect of microwave drying on the anti-diabetic potential of the leaves of Aquilaria subintegra and Aquilaria malaccensis with regard to its efficacy by local herbalists in the treatment of diabetes frailties. The drying process was carried out at 50, 100 and 150 W, and the drying curves were developed to analyse the drying characteristics of both species of Aquilaria leaves. Solid-liquid extraction was done by using ethanol as solvent prior to in-vitro analysis of the inhibition activity on α-amylase. Following that, HPLC and FTIR were done to support findings on the antidiabetic compounds of the leaves extract. The results indicated that an increase in power level will reduce the drying time during microwave treatment. Findings showed that both species of Aquilaria leaves extract could remarkably inhibit the activity of α-amylase and provide a rationale for the use of the leaves in the treatment of diabetes mellitus.

Microwave Drying of Sweet Potato (Ipomoea batatas (L.)) Slices: Influence of the Osmotic Pretreatment

2016 ◽  
Vol 367 ◽  
pp. 167-174 ◽  
Author(s):  
J.R.J. Junqueira ◽  
K.S. Mendonça ◽  
J.L.G. Corrêa
Keyword(s):  
Moisture Content ◽  
Mathematical Models ◽  
Sweet Potato ◽  
Microwave Power ◽  
Osmotic Dehydration ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Distribution Model ◽  
Drying Time ◽  
Osmotic Agents

Drying of sweet potato (Ipomoea batatas (L.)) slices by microwave with and without osmotic dehydration (OD) as a pretreatment was studied. Three osmotic agents (sucrose, sorbitol and fructose) were employed. Drying continued until final moisture content of 20 kg water 100 kg-1 sample. Two different microwave output powers (180 and 350W) were used. The drying kinetics was modeled by mathematical models from the literature. The use of OD and higher microwave power carried out to shorter drying time. Among the tested mathematical models, the Weibull distribution model presented good fitness for drying kinetics obtained in both microwave power.

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