Butylated hydroxytoluene addition improves the thiobarbituric acid assay for malonaldehyde from chicken plasma fat.

Samples of plasma lipid were tested for autoxidation during the heating step of the thiobarbituric acid (TBA) assay for malonaldehyde. Butylated hydroxytoluene (BHT) was used to quench sample autoxidation during the assay, and 25 ppm BHT was found effective in eliminating autoxidation in fresh plasma fat. At this concentration, BHT does not interfere with the reaction of malonaldehyde with TBA. Depending on fat concentration, absorbance at 532 nm was 2-5 times higher when samples were assayed without BHT compared to identical samples with 25 ppm BHT addition. It is concluded that BHT addition to the TBA assay before the heating step improves the reliability of the assay by eliminating autoxidation which may generate the majority of oxidative products measured in TBA assays lacking antioxidant protection.