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Modelling the dielectric properties of cow's raw milk under vat pasteurization

Abdullah, Suhail Najm and You, Kok Yeow and Khamis, Nor Hisham and Chong, Cheong Yew (2019) Modelling the dielectric properties of cow's raw milk under vat pasteurization. Progress In Electromagnetics Research M, 84 . pp. 157-166. ISSN 1937-8726


Official URL: http://dx.doi.org/10.2528/PIERM19052202


An efficient microwave milk pasteurization system requires a rigorous temperature dependent dielectric model of the milk, since the performance of milk pasteurization strongly depends on its dielectric properties. This paper describes the dielectric modelling of cow’s raw milk during batch (Vat) pasteurization which covers the frequencies from 0.2 GHz to 6 GHz. An open-ended coaxial sensor is used for the measurements of dielectric constant, loss factor, and ionic conductivity at temperature range of 25°C to 75°C with an interval of 5°C. Combinations of Cole-Davison and Debye equations are modified to fit the dielectric measurements. It was found that the measured dielectric constant decreased as the frequency increased, while the high temperature processed produce lower in a convergence manner toward 6 GHz. The loss factor exhibited high losses at higher temperature and lower frequencies, as well as converged at 1.9 GHz then diverged up to 6 GHz. Three relaxation processes are dominated at all temperature treatments within the frequency range. The relaxation time, τ, and the activation energy, Q, are modelled based on linear fitting of measured data according to Debye and Arrhenius approaches.

Item Type:Article
Uncontrolled Keywords:high temperature, lower frequencies
Subjects:T Technology > TK Electrical engineering. Electronics Nuclear engineering
Divisions:Electrical Engineering
ID Code:89448
Deposited By: Yanti Mohd Shah
Deposited On:22 Feb 2021 14:04
Last Modified:22 Feb 2021 14:04

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