Off-flavor odor development in lipids and lipid-containing foods is commonly attributed to the by-products of lipid peroxidation. Fats, oils, and other lipids react with oxygen to form peroxides, which then further decompose to give aldehydes, including malonaldehyde (MDA) and hexanal - both of which are associated with deterioration in meats. Factors affecting the formation of lipid peroxidation products include how the product was stored, cooked, processed, and the addition of preservatives.
The traditional method for detecting malonaldehyde is the 2-Thiobarbituric Acid Reactive Substances (TBARS) assay. In this reaction, one molecule of malonaldehyde is condensed with two molecules of 2-thiobarbituric acid under heated acidic conditions to form a pink chromogen. This assay has been modified many times since its discovery in the early 1960's and has always required heating to 100°C for longer than 30 minutes with a strong acid. Heating biological samples in an acidic solution generates colors that interfere with the TBARS assay and generates artificially high MDA values.
The OBR malonaldehyde quantitation kit is the first rapid TBARS assay that does not require heating, This feature makes the test more specific for malonaldehyde by greatly reducing the interferences generated at high temperatures.