Interference of sodium caseinate in the TBARS assay

One of the most common methods of measuring lipid oxidation in foods is the quantification of malonaldehyde by reaction with 2-thiobarbituric acid (TBA) in the so called TBA-reactive substances (TBARS) assay. Different variants of the TBARS assay include those in which the food sample reacts directly with the TBA reagent and those that involve collection of a distillate from the food before reaction with TBA. Interference of sodium caseinate (NaCas) in a TBARS assay involving direct reaction of TBA with a food sample was observed while exploring the possible retardation of lipid oxidation in sliced turkey meat coated with a NaCas-containing edible film. This short report shows the extent of interference encountered and illustrates the importance of validating the TBA method for particular applications.