FORMATION OF LACTULOSE AND FUROSINE DURING HEAT-TREATMENT OF MILK AT TEMPERATURES OF 100-120-DEGREES-C

The kinetics of formation of lactulose and furosine during heating of milk at 100-120 degrees C for 20 to 60 s were examined. Formation of l actulose and furosine could be described with apparent zero order reac tions (activation energies of 102.2 kJ/mol for lactulose and 104.1 kJ/ mol for furosine). The ratios of lactulose to furosine in heated sampl es were lower than those usually found in UHT milk. The correlation be tween the amount lactulose (y) and furosine (x) expressed as mg/l can be described by the equation: y = 4.30 x - 14.85 (+/- 5.49). These res ults also point out the contribution of the preheating of milk during the UHT process to the presence of lactulose and furosine in UHT milk samples.