MDA estimated according to Botsoglou et al. (11). In the presence of heat and acid, MDA reacts with thiobarbituric acid to produce a pink color complex, and the absorbance of the clear supernatant fraction has been read at 535 nm.
Frozen meat (2g) has been homogenized in 10 ml of sodium phosphate 100 mM, (pH 7) buffer with a homogenizer (WiseMix, Korea) for 1 min at high speed. The homogenate centrifuged at 8,000 g for 5 min and the supernatant used for MDA assay (12). (1.0 ml) of supernatant incubated with 1% (w/v) thiobarbituric acid in 50 mM NaOH (0.5 ml) and 2.8% (w/v) trichloroacetic acid (0.5 ml) in a boiling water bath for 15 min. surplus soluble proteins removed by centrifuging at 10,000 g for 5 min at 4 Cº. Results were calculated and expressed as mmol/g of fresh weight.
you can calculate TBARS level using molar extension coficeint equation