Comparison of methods for determining malondialdehyde in dry sausage by HPLC and the classic TBA test

A reproducible and sensitive HPLC assay with fluorometric detection for measuring malondialdehyde as an index of lipid peroxidation in dry sausage (salami) has been developed. Following the homogenisation of dry sausage in water, a solution of 5% ice-cooled trichloroacetic acid led to the precipitation of the proteins. The addition of thiobarbituric acid (TBA) (0.02 M) to the filtered mixture and its corresponding incubation (35 min, 100degreesC) completed the method. High correlation coefficients (r>0.977), with regard to the distillative TBA test, were obtained. Ratios between the HPLC and the distillation method of 2.23 were found. Also, the effect of the antioxidant BHT and an examination of the distillative classic TBA test have been done. Results indicate that this HPLC method, on account of its simplicity, sensitivity and specificity, may be preferred over the classic TBA test for estimating the rancidity of dry sausage.