Determination of oil oxidation by an aldehyde-requiring mutant of luminous bacteria

A simple, rapid bioluminescence test (BT) for the determination of lipid oxidation is described. The test utilizes an aldehyde-requiring dark mutant of Vibrio harveyi (M42) that emits light in the presence of long chain (C8-C16) aliphatic aldehydes. The procedure consists of treating the oil or fat with CO2+ ion in ethanolic medium at alkaline pH. This treatment facilitates the decomposition of the hydroperoxides into long-chain aldehydes, part of which is used by the bacteria to produce light. The test was evaluated with corn, soybean and safflower oils, and shows excellent correlation with the commonly used peroxide value assay.