NEW METHODOLOGIES FOR KINETIC-STUDY OF 5-(HYDROXYMETHYL)-FURFURAL FORMATION AND REACTIVE LYSINE BLOCKAGE IN HEAT-TREATED MILK AND MODEL SYSTEMS

New analytical techniques were used to study the kinetic behavior of 5 -(hydroxmethyl) furfural (HMF) and blockage of available lysine in mil k and model systems. Both determination of HMF by the chromatographic method and estimation of available lysine by the orthophthaldialdehyde (OPA) method at sterilization temperatures proved valid. Activation e nergies for the lysine loss reaction were 91.14, 112.41 and 66.67 kJ.m ol-1 in the model systems and the milk respectively in fluorimetric de termination with OPA. Activation energy for HMF determination ranged f rom 118.5 to 93.04 kJ.mol-1.