Effects of Deuterium Oxide on the Oxidative Stability and Change of Headspace Volatiles of Corn Oil

Abstract

AbstractEffects of deuterium oxide and deuterium oxide‐free water on the oxidative stability and formation of headspace volatiles were determined for corn oils to evaluate the role of moisture as an active influential factors during lipid oxidation. Mixtures of corn oil and water with different ratios of deuterium oxide were prepared, and the mixtures were stored at 60 °C for 2 days. Headspace oxygen contents, conjugated dienoic acid (CDA) values, and p‐anisidine values (p‐AV) were analyzed as a measure of oxidative stability, and headspace volatiles were analyzed by solid phase microextraction and a gas chromatography mass selective detector to determine the involvement of deuterium in volatiles. Deuterium oxide accelerated the rate of lipid oxidation in corn oil compared to oils with deuterium‐free water based on the results of headspace oxygen content, CDA, p‐AV, and total volatile content. Fragmented mass to charge ratios (m/z) of 73.1/72.1 for d1‐pentane/pentane and 57.0/56.0 for d1‐2‐propenal/2‐propenal from samples containing deuterium oxide were significantly higher than those from deuterium oxide‐free water, implying that moisture participated to form volatiles in corn oil oxidation under air‐tight condition. Deuterium oxide appeared to accelerate the rate of lipid oxidation in corn oils and participated to form volatiles from oils during oxidation.