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Dielectric characterization of vegetable oils during a heating cycle
Rosario Peñaloza-Delgado1, José Luis Olvera-Cervantes1, María Elena Sosa-Morales2
1Electronics Department, Instituto Nacional de Astrofísica, Óptica Y Electrónica, Tonanzintla, Puebla, México.
Journal of Food Science and Technology
|March 22, 2021
Summary
We measured the dielectric properties of vegetable oils like canola and olive oil up to 200°C. This data is crucial for microwave applications and high voltage engineering.
Area of Science:
- Materials Science
- Electrical Engineering
- Food Science
Background:
- Dielectric properties of oils are vital for microwave-assisted food processing and high voltage insulation.
- Understanding these properties at elevated temperatures is essential for optimizing industrial applications.
Purpose of the Study:
- To determine the complex permittivity of various vegetable oils (canola, olive, soybean, coconut) at 2.50 GHz.
- To investigate the effect of temperature (28–200 °C) on these dielectric properties.
- To assess changes in oil quality (free fatty acids, peroxide index, color) after heating.
Main Methods:
- Utilized the cavity perturbation technique with a cylindrical cavity operating at the TE111 mode.
- Performed measurements at a frequency of 2.50 GHz.
- Analyzed free fatty acids, peroxide index, and color before and after thermal treatment.
Main Results:
- Complex permittivity data was obtained for canola, olive, soybean, and coconut oils across the specified temperature range.
- The study provides insights into how temperature affects the dielectric behavior of these oils.
- Changes in oil quality parameters were quantified post-heating.
Conclusions:
- The dielectric properties of vegetable oils were characterized at microwave frequencies and elevated temperatures.
- This research offers valuable data for designing and improving microwave-based industrial processes and high-voltage equipment.
- The findings contribute to understanding oil stability under thermal stress.
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