Influence of composition, temperature, and frequency on dielectric properties of selected saltwater and freshwater fish

ABSTRACT

Dielectric heating has been applied in the fishing industry for thawing and cooking. However, the difference in dielectric properties for various species of fish can greatly influence the heating rate and uniformity. In this study, the dielectric properties of saltwater fish [Pomfret (Pampus argenteus) and Hairtail (Trichiurus lepturus)] and freshwater fish [Bream (Parabramis pekinensis) and Crucian Carp (carassius auratus)] were determined within the frequency range of 1–2500 MHz at –20°C to 100°C. Results showed that the dielectric constant (${\epsilon }^{\prime }$) and dielectric loss factor (${\epsilon }^{\prime \prime }$) of the four different species decrease with increasing frequency. The dielectric constants at 27.12 and 40.68 MHz increase with increasing temperature, and those at 915 and 2450 MHz increase rapidly and then decrease. The ${\epsilon }^{\prime }$ of Hairtail showed the highest increase, followed by Bream, Crucian Carp, and Pomfret; and the ${\epsilon }^{\prime \prime }$ of Hairtail showed the highest increase, followed by Pomfret, Bream, and Crucian Carp due to the composition difference between the species. Thus, the dielectric heating process for various species of fish can be considerably different at different frequencies. Furthermore, the most significant difference in dielectric properties among all species of fish was observed at 27.12 MHz, which indicated that this frequency could be the most suitable frequency for the detection of fish species based on their dielectric properties.

KEYWORDS:

• Fish
• Dielectric properties
• Composition
• Frequency
• Temperature

Acknowledgments

The author acknowledges China National Science Foundation (31801613, 31571866), China Postdoctoral Science Foundation (2018M632299), Shanghai Pujiang Program (16PJ1404100), and Professor of Special Appointment (Youth Eastern Scholar) at Shanghai Institutions of Higher Learning (No. QD2016055) for their financial support to this research. The authors have no conflict of interest to declare.

Additional information

Funding

This work was supported by the China Postdoctoral Science Foundation [2018M632299];National Natural Science Foundation of China [31801613].