scholarly journals FOAM-MAT DRYING KINETICS OF KEITT MANGO PULP

2017 ◽  
Vol 30 (1) ◽  
pp. 172-180 ◽  
Author(s):  
MARY KARLLA ARAÚJO GUIMARÃES ◽  
◽  
ROSSANA MARIA FEITOSA DE FIGUEIRÊDO ◽  
ALEXANDRE JOSÉ DE MELO QUEIROZ ◽  

ABSTRACT This study aimed to assess the foam-mat drying kinetics of mango pulp (cv. Keitt) adding 1% Emustab® and 1% Super Liga Neutra®, for a whipping time of 20 minutes, dried in a forced -air convection oven at different temperatures (50, 60 and 70oC) and foam layer thicknesses (0.5, 1.0 and 1.5 cm). Drying kinetic data were used to build drying curves and then fit to Page, Henderson, Henderson and Pabis, Logarithmic and two-term Exponential models. Both temperature and foam layer thickness influenced drying time, which reached the shortest value at the highest temperature and smallest thickness. The Page model provided the best fit to the experimental drying curve data.

Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  

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.


Author(s):  
Juan A. Cárcel ◽  
Matheus P. Martins ◽  
Edgar J. Cortés ◽  
Carmen Rosselló ◽  
Ramón Peña

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


2015 ◽  
Vol 14 (2) ◽  
pp. 18
Author(s):  
L. D. Do Nascimento ◽  
L. G. Corumbá ◽  
S. C. S. Rocha ◽  
O. P. Taranto ◽  
C. M. L. Costa ◽  
...  

In order to provide a contribution to future studies of foxtail millet (Setaria italica), the drying kinetics of the seeds was investigated at three different temperatures: 44, 65 and 86°C. The seeds of S. italica with a moisture equal to 30% in dry basis were dried in a conical-cylindrical spouted bed during an interval of 132 min. Some empirical mathematical models were selected to describe the experimental drying kinetics data (Lewis, Henderson and Pabis, Page, Diffusion approach, Midilli and Wang and Singh) and the best models were chosen according to the statistical tests results (coefficient of determination, mean relative percent deviation, mean square root error and residue distribution), using the software Statistica® 7.0 and applying the Quasi-Newton method. Only the decreasing rate period was observed in the drying kinetic curves, indicating that the removal of moisture content was preferably by the diffusion mechanism, which is a characteristic behavior of fibrous products, like the agricultural products. The models of Diffusion Aproach, Page and Midilli were the most suitable to describe the experimental drying curves.


Author(s):  
Nurhasmanina Norhadi ◽  
Ammar Mohd Akhir ◽  
Nor Roslina Rosli ◽  
Farid Mulana

Drying is generally used to increase the shelf life of food products. In this context, mango fruit is used as a sample for the drying process because of its high commercial value and particularly high moisture content. The mango was sliced into few batches of sample with a size of 20 mm × 30 mm × 5 mm each. The experiments were conducted using tray and oven dryer at different temperatures of 40, 50 and 60 °C with a steady airflow rate of 1.3 m/s. The objectives are to study the effect of drying time, temperature and air velocity towards drying of mango fruit, to compare the physical characteristics of mango sample after drying and to determine the best drying kinetics model fitted to each tray and oven dryer. The results showed that the increase in drying time, temperature and air velocity would reduce the moisture content while at the same time, drying rate increased significantly. Tray dryer was found to be more effective than oven dryer because of higher drying rate with better product quality and appearance at the end. Furthermore, the gathered data were fitted into few widely used drying mathematical models and it was found that Henderson and Pabis model at 60°C is best suited for tray dryer whereas Page model at 40 °C is the best for oven dryer.


Author(s):  
Plúvia O. Galdino ◽  
Rossana M. F. de Figueirêdo ◽  
Alexandre J. de M. Queiroz ◽  
Pablícia O. Galdino

ABSTRACT This study was conducted in order to obtain drying curves of whole atemoya pulp through the foam-mat drying method. The suspension was prepared with whole atemoya pulp mixed with 2% of Emustab® and 2% of Super Liga Neutra® with mixing time of 20 min, and dried in a forced-air oven at different temperatures (60; 70 and 80 °C) and thicknesses of the foam layer (0.5, 1.0 and 1.5 cm). The drying rate curves were plotted against the water content ratio and the semi-theoretical models of Henderson & Pabis, Page and Midilli were used. All tested models showed coefficient of determination (R2) above 0.993, and the Midilli model showed the best fit for all conditions. Drying curves were affected by temperature and layer thickness.


Author(s):  
Edmilson Silva Filho ◽  
Gilcean Silva Alves ◽  
Marco Tulio Lima Duarte ◽  
Thiago Murilo da Fonseca ◽  
Mary Karlla A. Guimarães

The aim of this work was to determine the drying kinetics in the foam layer of fresh cane broth with the addition of 2,0% Emustab®, 2,0% Super Neutral® and 1,0% phosphate At temperatures of 50, 60 and 70ºC and a total of 0,5 cm of thickness in the foam layer, which will be homogenized in the domestic mixer at the maximum speed for 30 min for foaming formation with approximately 0,500 g/cm3 of density . During the drying process in the foam layer, we monitored the drying kinetics by weighing the trays at regular intervals until we had constant weight. The drying data enabled the calculation of the values of the water content ratio and the construction of drying kinetics curves. Then we constructed the drying curves and adjusted the two-term models Henderson & Pabis, Henderson, Logarithmic, Page and Exponential to the experimental data of the drying kinetics. It was found that the drying temperatures influenced the drying time, in other words the shortest drying time was observed at the highest temperature. Drying times were 665, 545 and 485 minutes at temperatures of 50, 60 and 70°C whilst the thicknesses were 0,5 cm respectively. The drying time has been reduced more rapidly with the increase of the drying air temperature. The Henderson model was the one that described the most satisfactory data of the foam drying, presenting the highest coefficient of determination (0,9935) and the lowest square deviation (0,0007) at the temperature of 50 and thicknesses of 0,5 cm.


Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.


Author(s):  
Douglas R. Reis ◽  
Fabrício B. Brum ◽  
Eduardo J. O. Soares ◽  
Jessiana R. Magalhães ◽  
Fabrício S. Silva ◽  
...  

ABSTRACT Several types of seeds have been initially used in the food industry due to the great potential that vegetable proteins have. Baru is a fruit commonly found in the Cerrado biome, having a high nutritional value. This paper aimed to determine and analyze the drying kinetics of whole and defatted baru almond flours at different temperatures. The flour resulting from almond milling was defatted using petroleum ether. The drying processes were performed at temperatures of 40, 50 and 60 ºC. The mathematical models of Page, Henderson and Pabis, Midilli & Kucuk, Thompson and Approximation of Diffusion were fitted to the experimental data. The results showed a noticeable effect of air temperature on the drying kinetics of whole and defatted baru almond flours. According to the statistical parameters of analysis, the models Midilli & Kucuk and Page were the ones with the best fits to the experimental data. The effective diffusivity values found ranged from 8.02 × 10–10 to 19.90 × 10–10 m2 s-1 and for the activation energy were 22.39 and 39.37 KJ mol-1 for whole and defatted almonds, respectively.


Author(s):  
Chang Peng ◽  
Saeed Moghaddam

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.


Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 916 ◽  
Author(s):  
Kemal Çağatay Selvi

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).


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