1H LF-NMR Self-Diffusion Measurements for Rapid Monitoring of an Edible Oil’s Food Quality with Respect to Its Oxidation Status

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 18; p. 6064
• Main Authors: Osheter, Tatiana, Campisi-Pinto, Salvatore, Resende, Maysa T., Linder, Charles, Wiesman, Zeev
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 16.09.2022; MDPI
• Subjects: Aldehydes; Analytical chemistry; Canola; Chemical analysis; Chromatography; Cooking; Edible oils; Energy; Fatty acids; Food; Food quality; H relaxation; Laplace transforms; Morphology; NMR; Nuclear magnetic resonance; Oil and gas industry; Oils & fats; Oxidation; Physical properties; Polymerization; Self diffusion; Sensors; TD-NMR; Viscosity; Germany
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27186064

The food quality of edible oils is dependent on basic chemical and structural changes that can occur by oxidation during preparation and storage. A rapid and efficient analytical method of the different steps of oil oxidation is described using a time-domain nuclear magnetic resonance (TD-NMR) sensor for measuring signals related to the chemical and physical properties of the oil. The degree of thermal oxidation of edible oils at 80 °C was measured by the conventional methodologies of peroxide and aldehyde analysis. Intact non-modified samples of the same oils were more rapidly analyzed for oxidation using a TD-NMR sensor for 2D T1-T2 and self-diffusion (D) measurements. A good linear correlation between the D values and the conventional chemical analysis was achieved, with the highest correlation of R2 = 0.8536 for the D vs. the aldehyde concentrations during the thermal oxidation of poly-unsaturated linseed oils, the oil most susceptible to oxidation. A good correlation between the D and aldehyde levels was also achieved for all the other oils. The possibility to simplify and minimize the time of oxidative analysis using the TD NMR sensors D values is discussed as an indicator of the oil’s oxidation quality, as a rapid and accurate methodology for the oil industry.