Effect of Malondialdehyde on the Determination of Furosine in Milk-Based Products

For nutritional purposes the recombination of milk or milk proteins with polyunsaturated fatty acids had long been considered in newly designed products, such as functional foods. Four milk-resembling model systems were prepared having malondialdehyde content ups to 1 mM. Systems were heated between 110 and 150 °C for up to 30 min. The effect of the presence of bifunctional aldehydes on the determination of furosine as a heat-induced marker was investigated. Levels of 0.01 mM MAD in the reaction mixture could affect significantly the determination of furosine in a milk-based system. Impairment of lysyl residues through the analysis of furosine could be underestimated in the presence of malondialdehyde. Keywords: Malondialdehyde; furosine; lysine; Maillard reaction; milk