A novel approach to evaluate the temperature during drying of food products with negligible external resistance to mass transfer

• Published in: Journal of food engineering Vol. 114; no. 1; pp. 39 - 46
• Main Authors: Barati, E., Esfahani, J.A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-01-2013; Elsevier
• Subjects: air drying; air flow; Analytical solution; Biological and medical sciences; Biot number; Carrots; Convective drying; Diffusion; Drying; drying temperature; Evolution; Food engineering; Food industries; Foods; Fundamental and applied biological sciences. Psychology; General aspects; Heat and mass transfer; heat transfer; mangoes; Mass transfer; Mathematical analysis; Mathematical models; prediction; slabs; Convective drying; Heat and mass transfer; Analytical solution; Biot number; Resistance; Temperature; Solution; Heat transfer; Mass transfer; Food; Drying
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2012.07.028

► A reliable mathematical model that captures the history and distribution of temperature is presented. ► The main connotation of present study regards to establish the novel model for practical applications. ► The food temperature history can be obtained in a quick and efficient manner for practical applications. ► The value of aw tends to zero due to sharp reduction of surface moisture of food at early times of drying. ► Temperature ((T−Tc)/(Ts−Tc)) through z direction is the same for different Biot numbers at Fo>0.3.
The paper deals with modeling the convective drying process. A relevant and reliable mathematical model that captures the history and distribution of temperature is presented. The attention is focused on the simultaneous heat and mass transfer occurring during drying where dry and hot air flows about the food. In the present study, external resistance to mass transfer is considered negligible. As a result, the drying curve is almost independent of the boundary conditions, which means that drying is diffusion-controlled. The main connotation of present study regards to undertake analytical procedure to establish the novel model for practical applications. The results show that the temperature evolution can be evaluated from an advanced analytical solution in a quick and efficient manner. The model is validated with the literature experimental data obtained for carrot and mango slabs. A good agreement is obtained between the model predictions and the available experimental results.