Study of the drying behaviour and color kinetics of convective drying of yam (Dioscorea hispida) slices

2022 ◽  
Vol 176 ◽  
pp. 114258
Author(s):  
Monalisa Sahoo ◽  
Sushree Titikshya ◽  
Pramod Aradwad ◽  
Vivek Kumar ◽  
S.N. Naik
2014 ◽  
Vol 60 (No. 3) ◽  
pp. 92-99 ◽  
Author(s):  
V.A. REVASKAR ◽  
P.S. PISALKAR ◽  
P.B. PATHARE ◽  
G.P. SHARMA

The effect of different pre-treatments (i.e. osmotic dehydration in 10, 15 and 20°Brix NaCl solution and drying air temperature of 50, 60 and 70°C) on drying behaviour of onion slices were investigated. The onion slices were dried in a laboratory model tray dryer. Drying of onion slices occurred in falling rate period. Five thin-layer drying models (Exponential, Page, Henderson and Pabis, Logarithmic and Power law) were fitted to the moisture ratio data. Among the drying models investigated, the Page model satisfactorily described the drying behaviour of onion slices. The effective moisture diffusivity of pre-treated samples was higher than that of non-treated samples


2021 ◽  
Vol 9 (16) ◽  
pp. 212-220
Author(s):  
Liubomyr Khomichak ◽  
◽  
Inha Kuznietsova ◽  
Svetlana Vysotska ◽  
Sergiy Tkachenko ◽  
...  

Introduction. Processing of grain raw material with influence on starch or albumens by application of heat treatment creates the variety of functional properties of a product and is perspective in the modern terms vital functions of man. Research methods and methods. The flour obtained from wheat of the Ascanian wheat and from wheat of the soft varieties: Sophia ("sweet wheat"), Blond (soft) and Chornobrova (enriched with micro- and macronutrients) were used in the study. Thermal modification of flour samples was carried out in a convective manner. The control sample for determining the quality indicators is obtained in industrial conditions, extruded wheat flour produced by LLC "AS groups, LTD". Research results. The obtained kinetic dependence shows the gradual loss of moisture standards with different speed which accordingly influences on duration of drying. The moisture content of the drying agent most affects the intensity at the initial stage of the constant drying rate. With an increase in the moisture content of the coolant, the period of constant drying increases and the amount of evaporated moisture increases during this period. With the subsequent removal of moisture from raw materials, the degree of influence of this parameter on the intensity decreases. The nature of the drying curves is the same and the recommended process for obtaining modified flour is the process duration of 300 minutes or 5 hours. It was determined microscopically, that the samples of dried wheat flour have a purpose and are partially destroyed by starch granules and amorphization of biocomposite materials. Based on the data on the kinetics of drying flour samples, the kinetic coefficients and values of the critical moisture content for drying wheat flour were calculated, which is 1.18-1.30 %. It was determined that for the sensorial indicators the obtained samples have indicators characteristic of the varietal characteristics of wheat, from which the flour was taken. In terms of physical and chemical parameters, the modified wheat flour samples are not inferior to the well-known industrial sample of extruded flour. Conclusions. Use of flour, obtained from the wheat with different correlation of amilose and amylopectin, positively influences on a technological process and allows to extend the assortment of modified starch products, and accordingly, food products. Kinetics of the convective drying standards of the flour is investigated. Researches showed that a it is physically modified flour obtained from the different sorts of the soft wheat is not inferior in quality to the extruded wheat flour.


2019 ◽  
Vol 11 (3) ◽  
pp. 211-220
Author(s):  
M. Doganturk ◽  
E. Demiray ◽  
O. Gursoy ◽  
Y. Yilmaz

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.


2014 ◽  
Vol 6 ◽  
pp. 830387 ◽  
Author(s):  
Wei Cai ◽  
Lexian Zhu ◽  
Shilin Dong ◽  
Guozhen Xie ◽  
Junming Li

The convective drying kinetics of porous medium was investigated numerically. A mathematical model for forced convective drying was established to estimate the evolution of moisture content and temperature inside multilayered porous medium. The set of coupled partial differential equations with the specified boundary and initial conditions were solved numerically using a MATLAB code. An experimental setup of convective drying had been constructed and validated the theoretical model. The temperature and moisture content of the potato samples were dynamically measured and recorded during the drying process. Results indicate that thermal diffusion coefficient has significant positive impact on temperature distribution and mass diffusion coefficient might directly affect the moisture content distribution. Soret effect has a significant impact on heat flux and temperature distribution in the presence of large temperature gradient.


2019 ◽  
Vol 20 (2) ◽  
Author(s):  
A. T. Naseri ◽  
E. Cetindag ◽  
J. Forte ◽  
E. Bilgili ◽  
Rajesh N. Davé

2018 ◽  
Vol 54 (10) ◽  
pp. 3117-3130 ◽  
Author(s):  
Frederick Sarpong ◽  
Xiaojie Yu ◽  
Cunshan Zhou ◽  
Patricia Oteng-Darko ◽  
Leticia Peace Amenorfe ◽  
...  

2013 ◽  
Vol 9 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Juliana M. Silva ◽  
Muriel G. Cantu ◽  
Vera Rodrigues ◽  
Marcio A. Mazutti

AbstractThis work evaluated the effects of osmotic dehydration on convective drying kinetics of figs. It used the experimental design methodology to evaluate the influence of sucrose concentration, temperature and time on the amount of total soluble solids (TSS) and moisture content of the figs. After the osmotic dehydration, it evaluated the convective drying kinetics at temperatures from 55 to 75°C. A mathematical model was employed to fit the experimental data. From the experimental data of the osmotic dehydration, it was seen that the moisture content of the figs after the treatment was closely related to the amount of TSS of the figs. Low moisture content and high TSS content were obtained for a narrow range of independent variables comprised between 55–60°C, 55–63 wt% and 260–280 min for temperature, sucrose concentration and exposure time, respectively. In the convective drying kinetics of the figs, there were no verified significant differences in the final time of drying of non-treated and osmotically dehydrated figs. However, the shrinkage was considerably reduced in the osmotically treated figs. The use of osmotic treatment enables the obtainment of figs softer than the simple use of convective drying without changing the final time of drying.


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