2.4.7. Determination of thiobarbituric acid reactive substances
(TBARS)
Thiobarbituric acid-reactive substances (TBARS) were determined
as described by Buege and Aust (1978). A ground sample
(0.5 g) was homogenised with 2.5 ml of a solution containing
0.375% (w/v) thiobarbituric acid, 15% (w/v) trichloroacetic acid
and 0.25 mol/l HCl. The mixture was heated in a boiling water bath
(95–100 C) for 10 min to develop a pink colour, cooled with running
tap water and centrifuged at 3,600 g at 25 C for 20 min.
The absorbance of the supernatant was measured at 532 nm. A
standard curve was prepared using 1,1,3,3-tetramethoxypropane
at concentrations ranging from 0 to 10 ppm. TBARS was calculated
and expressed as mg malonaldehyde/kg dry sample.