ALDEHYDES IN FOOD AND ITS RELATION WITH THE TEA TEST FOR RANCIDITY

Aldehydes have been found in fruits and essential oils. But their presence in the off-flavor compounds (rancidity of foods) is well known. Aldehydes are characteristic compounds of secondary oxidation in the autoxidative process of fats, oils, lipidic foods and biological membranes. Malonaldehyde and other aldehydes responsible for rancidity can be evaluated through the thiobarbituric acid (TEA) assay. Alkanals, alkenals and dienals give characteristic pigments (yellow, orange, red pigments) with TEA reagent, which could be spectrophotometrically evaluated.