Dielectric properties and dipole moment of edible oils subjected to ʼfryingʼ thermal treatment

Šegatin, Nataša (avtor), Pajk Žontar, Tanja (avtor), Poklar Ulrih, Nataša (avtor)

The dielectric properties of six refined edible oils with different fatty-acid compositions were determined for oils incubated at 180 °C up to 40 h. The oil degradation was evaluated by the dielectric dispersion and dielectric loss in the frequency range from 40 Hz to 2 MHz at 25 °C, refractive index, density, saponification number, and specific absorption coefficient at 232 and 268 nm. The dependence of the dielectric properties on frequency has been evaluated with Corach, Cole–Cole, and the universal power law models, giving the novel strategies for the interpretation of the dielectric spectra of thermally treated oils. The derived parameters—the dielectric constant, the electrical conductivity, the relaxation time τ and the exponents α, p, and n—are discussed with respect to the increased oxidation evidenced by specific absorption coefficients and polar products, as measured by the dielectric constant of the thermally treated oils. The specific refraction, specific polarization, orientation polarization, and dipole moment were determined using Lorenz–Lorentz, Debye and Onsager relationship. All above parameters obtained increased during the thermal treatment, except specific refraction, the electrical conductivity and the relaxation time. The dielectric constant-macroscopic parameter was compared with microscopic parameter polarization and dipole moment; the linear dependence was found to be R$^2$ = 0.971.

• Jezik: Angleški jezik
• Ključne besede: edible oils, dielectric constant, electrical conductivity, dipole moment, polarization, refraction
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: BF - Biotehniška fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2020
• Št. strani: 17 str.
• Številčenje: Vol. 9, iss. 7, art. 900
• PID: 20.500.12556/RUL-128309
• UDK: 544.623:664.34
• ISSN pri članku: 2304-8158
• DOI: 10.3390/foods9070900
• COBISS.SI-ID: 22479875
• Datum objave v RUL: 08.07.2021

Gradivo je del revije

• Naslov: Foods
• Skrajšan naslov: Foods
• Založnik: MDPI
• ISSN: 2304-8158
• COBISS.SI-ID: 512252472

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.
• Začetek licenciranja: 08.07.2020

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: jedilna olja, toplotna obdelava, električna prevodnost, dielektrične lastnosti, dipolni moment

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: P4-0121
• Naslov: Biokemijska in biofizikalno-kemijska karakterizacija naravnih snovi