Controlled-potential electrolysis antioxidant effects on edible oils

Authors: YASIN, LEEN - University Of Michigan; THELEN, MATTHEW - University Of Michigan; Moser, Jill; FHANER, MATTHEW - University Of Michigan

Submitted to: European Journal of Lipid Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Deep-fat frying exposes oils to high heat and oxygen, which can rapidly degrade frying oils, resulting in loss of nutrients and the formation of potentially harmful compounds if these reactions are not carefully monitored and controlled. Antioxidants and anti-polymerization agents are added to oils to slow down these reactions during frying to extend the frying life of oils and maintain the quality of fried foods. However, antioxidants are also degraded and evaporated by high temperatures and must be monitored and replenished. In this study, instead of using antioxidants to prevent oil degradation during frying, researchers used a platinum electrode to apply voltage to safflower, peanut, and soybean oil while they were heated to frying temperature. The degradation of polyunsaturated fatty acids in oils that were treated with voltage was compared to degradation of untreated samples. It was found that the voltage treatment protected the polyunsaturated fatty acids in the oils from degradation. The researchers also determined the level of voltage that had the most protective effect. Although more work needs to be done to understand the impact of this treatment on frying oil and, ultimately fried food quality, the results present a possible new avenue for protection of frying oils from degradation during frying without the need for adding synthetic antioxidants. This may be of interest to food companies, oilseed processors, as well as frying equipment manufacturers and potentially lead to more plant-based oils being used as frying oils thus more income sources for American farmers.

Technical Abstract: Thermal oxidation of unsaturated fatty acids occurs in edible oils during processing, shipping and storage, and consumer use. Numerous antioxidant strategies have been employed to slow oxidation rates in an effort to preserve the healthfulness and flavor characteristics of these products. In these studies, an applied voltage was utilized as an antioxidant strategy for the preservation of unsaturated fatty acids exposed to high temperatures. Initially, three edible oils (peanut, safflower, and vegetable) were exposed to a cathodic voltage of -0.6V vs. Ag/AgCl and reduction in polyunsaturated fatty acids were measured via square-wave voltammetry and gas chromatography with flame ionization detection. It was observed that an applied cathodic voltage decreased the rate of oxidation for linoleic and linolenic acids for all three oils tested. These results prompted an expanded study to further understand how the magnitude of the applied voltage impacted fatty acid degradation. Results suggest that more negative applied voltages produce a higher protective effect for unsaturated fatty acids. Additionally, as the voltage is increased to more positive values, the protective effect is eventually lost, and a deleterious effect is observed. The inflection point between protective and degenerative effects occurs near the formal oxidation potential for a redox reaction. These results suggest that a tailored antioxidant strategy for different oil blends may be feasible without the need for chemical additives.