Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes

Aberham Hailu Feyissa, Niels Bøknæs, P.L. Nielsen, Stina Frosch

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

Abstract

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.
Original languageEnglish
Publication date2016
Publication statusPublished - 2016
Event12th 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 201518 Jun 2015

Conference

Conference12th International Congress on Engineering and Food
LocationQuébec 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
CountryCanada
CityQuébec City
Period14/06/201518/06/2015

Cite this

Feyissa, A. H., Bøknæs, N., Nielsen, P. L., & Frosch, S. (2016). Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes. Abstract from 12th International Congress on Engineering and Food, Québec City, Canada.
Feyissa, Aberham Hailu ; Bøknæs, Niels ; Nielsen, P.L. ; Frosch, Stina. / Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes. Abstract from 12th International Congress on Engineering and Food, Québec City, Canada.
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Feyissa, AH, Bøknæs, N, Nielsen, PL & Frosch, S 2016, 'Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes' 12th International Congress on Engineering and Food, Québec City, Canada, 14/06/2015 - 18/06/2015, .

Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes. / Feyissa, Aberham Hailu; Bøknæs, Niels; Nielsen, P.L. ; Frosch, Stina.

2016. Abstract from 12th International Congress on Engineering and Food, Québec City, Canada.

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

TY - ABST

T1 - Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes

AU - Feyissa, Aberham Hailu

AU - Bøknæs, Niels

AU - Nielsen, P.L.

AU - Frosch, Stina

PY - 2016

Y1 - 2016

N2 - 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.

AB - 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.

M3 - Conference abstract for conference

ER -

Feyissa AH, Bøknæs N, Nielsen PL, Frosch S. Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes. 2016. Abstract from 12th International Congress on Engineering and Food, Québec City, Canada.