2-Thiobarbituric Acid as a Reagent for Detecting Milk Fat Oxidation

Abstract

Malonic dialdehyde has been shown to yield a red color when heated with 2-thiobarbituric acid (TBA) reagent. Spectral analysis of this color has revealed it to be identical with that obtained similarly from oxidized milk fat and to closely resemble colors secured in like manner from a number of oxidized lipid materials and animal tissues containing unsaturated fatty acids. Thus, malonic dialdehyde may be a compound of significance in both food fat rancidification and the biological oxidation of unsaturated fatty acids. A preliminary study concerning the use of TBA to measure oxidative deterioration in pure milk fat has indicated that this reagent is more sensitive than conventional tests such as iodine value and the Kreis test. A procedure for empirical measurement of milk fat oxidation with the TBA reagent is presented. It seems probable that the TBA test could be used advantageously in measuring oxidative deterioration in a wide variety of fats and fat-containing foods. © 1951, American Dairy Science Association. All rights reserved.