Heat treatment is an important process in the manufacturing of a wide range of solid foods. When food products of different sizes (e.g. cooking of shrimps) are processed with the conventional thermal processes, the products are heated unevenly where the small bodies are overcooked and the large bodies are undercooked. Ohmic heating (OH) is one of the novel technologies potentially solving this problem. However, the ability to predict and optimize the resulting temperature profile in solid foods processed by OH rests on a better understanding of the fundamental aspects of OH and of the physical factors leading to variations and uncertainties in prediction of the right process parameters. The current work is focused on modelling of OH of solid food pieces of varying sizes cooked in one batch. A 3D mathematical model of coupled heat transfer and electric field during OH of shrimps has been developed. The mathematical model has been formulated from mechanistic understanding of the process. The resulting coupled model equations were solved using the Finite Element Method (COMSOL Multiphysics® version 4.3b). Experiments were carried out using a newly developed laboratory-scale ohmic heater where the product (shrimps of different sizes) was immersed in the water with (1-2% salt solution). Temperature profiles and current were measured during the experiment and the model has been validated using the experimental data. Good agreement has been achieved between model predictions and the experimental values. The temperature distributions including the cold and hot spots have been predicted inside unpeeled shrimp (that consist of head, meat and other parts). Furthermore the effect of the voltage and salt concentration on the temperature distribution were also investigated.Through the development of this model a better understanding of OH has been obtained. The model can be used for the optimization, upscaling and design of OH of shrimps.
|Publication status||Published - 2016|
|Event||12th International Congress on Engineering and Food - Québec City Convention Centre / Société du Centre des congrès de Québec | 900, boul. René‐Lévesque Est, 2e étage | Québec G1R 2B5 | 418 649‐7711 poste 4032, Québec City, Canada|
Duration: 14 Jun 2015 → 18 Jun 2015
|Conference||12th International Congress on Engineering and Food|
|Location||Québec City Convention Centre / Société du Centre des congrès de Québec | 900, boul. René‐Lévesque Est, 2e étage | Québec G1R 2B5 | 418 649‐7711 poste 4032|
|Period||14/06/2015 → 18/06/2015|