scholarly journals Drying Kinetics of Curcuma xanthorrhiza Roxb.

2017 ◽  
Vol 3 (5) ◽  
pp. 110 ◽  
Author(s):  
Lanny Sapei ◽  
Elieser Taringan ◽  
Lie Hwa ◽  
Violita Putri Halim ◽  
Fhelix August Soebiantoro
Keyword(s):  
Drying Kinetics ◽  
Tropical Region ◽  
Drying Time ◽  
Traditional Medicines ◽  
Healing Power ◽  
Herbal Plants ◽  
Curcuma Xanthorrhiza ◽  
Quality Of Products ◽  
Kinetics Of

<p class="Els-Abstract-text"><em>Curcuma xanthorrhiza </em>Roxb. (giant curcuma) is one of herbal plants which is easily found in tropical region such as in Indonesia and has been widely used for medical purposes. This plant has been intensively used as the main ingredients of traditional medicines due to its potent healing power. Giant curcuma is generally dried using a conventional way under the sun prior to use. This method was less controlled, thus leading to poorer quality of products. Drying in a controlled batch dryer could improve product quality in overall. This experiment aimed to study the drying kinetics of giant curcuma using a laboratory designed batch dryer. Drying temperatures were varied between 40°C to 60°C. Samples were also dried in the oven at corresponding temperatures as the control. The drying was conducted until approximately 11 % dry basis moisture content inside the samples was achieved. In general, the drying time of giant curcuma were shorter when the temperatures were increased. This was also confirmed by Page’s Model whereby drying rate constants increased four times both in the batch dryer as well as in the oven when the drying temperatures were increased from 40°C to 60°C.</p>

scholarly journals Influence of the temperature and ultrasound application in drying kinetics of apple skin

2018 ◽  
Author(s):  
Juan A. Cárcel ◽  
Matheus P. Martins ◽  
Edgar J. Cortés ◽  
Carmen Rosselló ◽  
Ramón Peña
Keyword(s):  
Physical Structure ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Different Temperatures ◽  
Ultrasound Application ◽  
Quality Of Products ◽  
Drying Conditions ◽  
Kinetics Of ◽  
By Products

The great amount of waste produced by food industry contains interesting bioactive compounds. The extraction of these compounds requires the by-products previous stabilization being the convective drying one of most used techniques to this end. Drying conditions can affect both drying kinetics and final quality of products. The apple skin, byproduct of apple juice or cider industries, is rich in functional compounds such as polyphenols or vitamin C. The main goal of this contribution was to quantify the influence of temperature and ultrasound application in drying kinetics of apple skin. For this purpose, drying experiments at different temperatures (-10, 30, 50 and 70 ºC) and with (20.5 kW/m3) and without application of ultrasound were carried out. Drying kinetics were modelled by using a diffusion based model. As can be expected, the higher the temperature the faster the drying. Ultrasound application accelerated the process at every temperature tested being the influence slightly lower than found from the literature for other products. This can be attributed at the physical structure of the apple skin, less porous than the pulp. In any case, the application of ultrasound significantly reduced the drying time. Keywords: by-products; dehydration;diffusivity; mass transfer

scholarly journals Mathematical modeling of pequi pulp drying and effective diffusivity determination

2017 ◽  
Vol 21 (7) ◽  
pp. 493-498 ◽  
Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Air Speed ◽  
Drying Curves ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

scholarly journals Drying Modelling, Moisture Diffusivity and Sensory quality of Thin Layer dried Beef

2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri
Keyword(s):  
Thin Layer ◽  
Sensory Quality ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Slice Thickness ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying

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.

Experimental Evaluation and Kinetic Analysis of Direct-Contact Ultrasonic Fabric Drying Process

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Chang Peng ◽  
Saeed Moghaddam
Keyword(s):  
Direct Contact ◽  
Ultrasonic Transducer ◽  
Gaussian Model ◽  
Weibull Model ◽  
Drying Kinetics ◽  
Energy Prices ◽  
Drying Process ◽  
Liquid Form ◽  
Drying Time ◽  
Kinetics Of

Abstract Over the past two decades, due to the rising energy prices and growing awareness about climate change, significant efforts have been devoted to reducing the energy consumption of various home appliances. However, the energy efficiency of clothes dryers has little improvement. Recent innovations in the direct-contact ultrasonic fabric drying technique offer new opportunities for energy saving. In this technique, high-frequency mechanical vibrations generated by the ultrasonic transducer are utilized to atomize water from a fabric in the liquid form, which demonstrates great potential for reducing energy use and drying time of the fabric drying process. Here, for the first time, fabric drying kinetics under different direct-contact ultrasonic drying conditions were investigated experimentally and analytically. The drying processes of four kinds of fabrics were experimentally tested under different ultrasonic transducer vibration frequency (115, 135, and 155 kHz) and input power (1.2, 2.5, and 4.4 W) conditions. According to the experimental data, five different kinds of models were applied to quantify the drying kinetics of fabrics during direct-contact ultrasonic drying. The models not only incorporated the transducer parameters but also the parameters related to the nature of fabric. Our evaluation results of model prediction performance demonstrated that the two empirical models, i.e., the Weibull model and the Gaussian model, were superior to the three semi-theoretical models for anticipating the drying kinetics of fabrics under direct-contact ultrasonic drying. Furthermore, the Weibull model is more suitable for practical energy-efficient direct-contact ultrasonic fabric drying applications compared with the Gaussian model.

scholarly journals Investigating the Influence of Infrared Drying Method on Linden (Tilia platyphyllos Scop.) Leaves: Kinetics, Color, Projected Area, Modeling, Total Phenolic, and Flavonoid Content

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 916 ◽  
Author(s):  
Kemal Çağatay Selvi
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Total Phenolic ◽  
Flavonoid Content ◽  
Projected Area ◽  
Drying Time ◽  
Tilia Platyphyllos ◽  
Drying Behavior ◽  
Kinetics Of ◽  
And Diffusion

The Linden (Tilia platyphyllos Scop.) is a highly popular herbal plant due to its central nervous system properties. In this study, thin layer drying kinetics of linden leave samples were experimentally investigated in an infrared (IR) dryer. In order to select the appropriate model for predicting the drying kinetics of linden leaves, eleven thin layer semi theoretical, theoretical, and empirical models, widely used in describing the drying behavior of agricultural products, were fitted to the experimental data. Moreover, the color, projected area (PA), total phenolic content (TPC), and total flavonoid content (TFC) were investigated. The results showed that the drying time decreased from 50 min to 20 min. with increased IR temperature from 50–70 °C. Therewithal, the Midilli model gave the most suitable data for 50 °C, 60 °C. Moreover, Verma et al. and Diffusion approximation models showed good results for 70 °C. The lightness and greenness of the dried linden leaves were significantly changed compared with fresh samples. The PA of dried sample decreased similar to the drying time. In addition, the drying temperature effect on the effective diffusion diffusivity (Deff) and activation energy (Ea) were also computed. The Deff ranges from 4.13 × 10−12 to 5.89 × 10−12 and Ea coefficient was 16.339 kJ/mol. Considering these results, the Midilli et al. model is above the 50 °C, 60 °C, and the Verma et al. and Diffusion to 70 °C, for explaining the drying behavior of linden leaves under IR drying. Moreover, it can be said that the Page model can be used, if it is desired, to express the drying behaviors, partially with the help of a simple equation material by drying. TPC and TFC values were statistically < 0.001 higher in dried samples compared to fresh samples; however, no change has been recorded of TPC and TFC values at different temperatures (50 °C, 60 °C, 70 °C).

scholarly journals Physiological and sensorial quality of Arabica coffee subjected to different temperatures and drying airflows

2017 ◽  
Vol 39 (2) ◽  
pp. 225 ◽  
Author(s):  
Guilherme Euripedes Alves ◽  
Flávio Meira Borém ◽  
Eder Pedroza Isquierdo ◽  
Valdiney Cambuy Siqueira ◽  
Marcelo Ângelo Cirillo ◽  
...  
Keyword(s):  
Germination Percentage ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Drying Time ◽  
Physiological Variables ◽  
Different Temperatures ◽  
Negative Effect ◽  
Physiological Quality ◽  
Sensorial Quality

The objective of this study was to evaluate the correlation between a group of physiological variables (electrical conductivity, potassium leaching, and germination percentage) and a group of drying kinetics variables (drying time and drying rate) in addition to verifying the relation between drying kinetics variables and coffee quality as a function of processing type, temperature, and drying airflow. Coffee drying was conducted in a fixed-layer dryer at two temperatures and two airflows. After drying, an evaluation of the physiological and sensorial quality was conducted. Based on the results obtained, the following conclusions were drawn: coffee that is processed via a dry method is more sensitive to mechanical drying with heated air than coffee processed via a wet method, resulting in poor physiological performance; airflow does not interfere with the physiological quality of pulped and natural coffees; a temperature increase from 40 to 45°C resulted in a decrease in the physiological quality only for pulped coffee; and an increase in the drying rate as a result of an increase in the drying temperature to 40°C had a negative effect on the sensorial quality of pulped coffee. 

Comparison of Drying Kinetics of Maize in Oven and in Pilot Silo Dryer: Influence on Moisture Content and Physical Characteristics

2016 ◽  
Vol 12 (6) ◽  
pp. 599-606 ◽  
Author(s):  
Flávia Daiana Montanuci ◽  
Raphaela Mulato Cavalcante ◽  
Camila Augusto Perussello ◽  
Luiz Mario de Matos Jorge
Keyword(s):  
Moisture Content ◽  
Temperature Increase ◽  
Drying Kinetics ◽  
Final Moisture Content ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Temperature ◽  
Design And Optimization ◽  
Process Kinetics ◽  
Kinetics Of

Abstract The study of process kinetics may aid the design and optimization of drying systems. This paper evaluated the influence of drying temperature (40, 60 and 80 °C) on the moisture content, drying rate, density, shrinkage and breakage of maize dried in two different dryers: oven and silo dryer. In both dryers, the temperature increase reduced drying time, final moisture content and shrinkage of the grains, however increased breakage. Drying rate was higher in the oven (6.4×10−4±2.3×10−4s−1 versus 5.4×10−4±1.2×10−4s−1), while shrinkage (15.2±4.7 % versus 24.4±5.6 %) and density increase (16.6±5.9 % versus 33.4±5.8 %) were more intense in the silo. There was a large release of husk in the silo dryer and the moisture content was slightly smaller in the lower layers respective to the upper ones.

Effect of Air Velocity and Temperature on the Drying Kinetics of Drumstick Leaves (Moringa Oleifera)

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Monica Premi ◽  
Harish Sharma ◽  
Ashutosh Upadhyay
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Moringa Oleifera ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Drying Time ◽  
Effective Moisture ◽  
Kinetics Of

Abstract The present study examines the effect of air velocity on drying kinetics of the drumstick leaves in a forced convective dryer. The drumstick leaves were dried in the temperature range of 50–800 C, at different air velocity (Dv) of 0.5 and 1.3 m/s. The results indicated that drying temperature and air velocity are the factors in controlling the drying rate. Experimental data obtained for the samples for color, drying rate and drying time proved that air velocity of 1.3 m/s yielded the product superior in terms of both quality and energy efficiency as compared to the samples at 0.5 m/s. Activation energy for drumstick leaves dried with air velocity, 0.5 and 1.3 m/s was 12.50 and 32.74 kJ/mol respectively. The activation energy relates similarly with the effective moisture diffusivity which also increased with increase in air velocity and temperature.

scholarly journals Kinetics of Drying and Physical-Chemical Quality of Peach cv. Hubimel

2019 ◽  
Vol 11 (16) ◽  
pp. 223
Author(s):  
Newton C. Santos ◽  
Sâmela L. Barros ◽  
Shênia S. Monteiro ◽  
Semirames do N. Silva ◽  
Victor H. de A. Ribeiro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Models ◽  
Effect Of Temperature ◽  
Initial Time ◽  
High Water Content ◽  
Chemical Quality ◽  
Drying Time ◽  
Physical Chemical ◽  
Kinetics Of

The objective of this study was to perform the kinetics of peach drying and to adjust the experimental data obtained to empirical and diffusive mathematical models to evaluate the effect of temperature on the physical-chemical quality of the final product. The drying experiments were performed in an air circulation dryer with a velocity of 1.5 m s-1, the drying kinetics were performed at temperatures of 60, 70 and 80 &deg;C. Among the mathematical models applied, the Page model was the one that best fit the experimental data, because it presents greater efficiency in the description of the drying process. The decrease in the drying rate from the initial time to the end of the process was observed, increasing the temperature of the air caused a reduction in the drying time. It was verified through the analytical solution of the diffusion equation with infinite wall geometry that the increase of the drying temperature caused the increase of the diffusivity and convective coefficient of heat transfer. Through the Biot number, it can be stated that the first-type boundary condition would also describe the process satisfactorily. The fresh peach slices present high water content and water activity and the drying effect caused significant differences in all physical-chemical parameters analyzed.

scholarly journals Microwave assisted convective drying of kale (Brassica oleracea L. var. sabellica L.) at stationary and non-stationary conditions

2018 ◽  
Author(s):  
Dominik Mierzwa ◽  
Justyna Szadzińska
Keyword(s):  
Ascorbic Acid ◽  
Convective Drying ◽  
Drying Time ◽  
High Power Microwave ◽  
Microwave Application ◽  
Colour Measurements ◽  
Stationary Conditions ◽  
Quality Of Products ◽  
Power Microwave

This paper concerns hybrid drying of kale. Eight different schedules of drying were tested experimentally to find out the influence of microwave enhancement on the kinetics (drying rate and time), energy consumption of convective drying and quality of products. Different power of microwaves and modes of microwave application were tested. Quality of products was assesed through water activity and colour measurements, as well as retention of ascorbic acid. The results obtained in the studies allowed to state that intermittent application of high-power microwave pulses may lead to a meaningful reduction of drying time and high quality of the dry products.Keywords: hybrid drying; intermittent drying; kale; ascorbic acid; colour  

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