Effect of malondialdehyde on the determination of furosine in milk-based products

For nutritional purposes the recombination of milk or milk proteins with po lyunsaturated fatty acids had long been considered in newly designed produc ts, such as functional foods. Four milk-resembling model systems were prepa red having malondialdehyde content ups to 1 mM. Systems were heated between 110 and 150 degrees C for up to 30 min. The effect of the presence of bifu nctional aldehydes on the determination of furosine as a heat-induced marke r was investigated. Levels of 0.01 mM MAD in the reaction mixture could aff ect significantly the determination of furosine in a milk-based system. Imp airment of lysyl residues through the analysis of furosine could be underes timated in the presence of malondialdehyde.