|LI, XUAN - University Of California|
Submitted to: Food and Bioprocess Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2013
Publication Date: 10/30/2013
Citation: Li, X., Pan, Z. 2013. Predictive modeling of infrared radiative heating in tomato dry-peeling process: Part I. Model development. Food and Bioprocess Technology. 7:1996-2004.
Interpretive Summary: The predictive mathematical model can be a starting step to gain insight into the rapid surface heating characteristics of IR radiation in the tomato dry-peeling process. A three dimensional heat transfer model was developed to predict the temperature changes on the surface and within a tomato under the typical IR dry-peeling condition. . Simulation results illustrated that IR heating induced a dramatic temperature increase on the tomato surface which extended 0.6 mm beneath (>90°C) during a 60 s heating period and the interior temperature at the tomato center remained low (<30°C). The low temperature in the center indicates firmer product that can be obtained by using IR peeling. This modeling approach could also be extended for studying other fruits and vegetables under IR dry-peeling.
Technical Abstract: Infrared (IR) dry-peeling has emerged as an effective non-chemical alternative to conventional lye and steam methods of peeling tomatoes. Successful peel separation induced by IR radiation requires the delivery of a sufficient amount of thermal energy onto tomato surface in a very short duration. The objectives of this study were to understand the transient heat transfer phenomena during IR dry-peeling by developing a computer simulation model. Modeled tomatoes with realistic shapes and different sizes were employed to predict the temperature distributions on their surface and interior during a 60 s IR heating. IR radiation was postulated as a mathematically gray-diffuse radiation problem based on the enclosure theory. Radiation heat transfer model combining heat conduction and convection was solved numerically in COMSOL by using a finite element scheme. Influence of the temperature-dependent thermal properties and phase change was studied with improved model accuracy. Simulation results illustrated that IR heating induced a dramatic temperature increase on the tomato surface which extended 0.6 mm beneath (>90°C) during a 60 s heating period and the interior temperature at the tomato center remained low (<30°C). The developed model can further be used to study the effects of IR heating configurations on the IR heating performance of tomatoes.