MAILLARD REACTION IN MICROWAVE COOKING - COMPARISON OF EARLY MAILLARDPRODUCTS IN CONVENTIONALLY AND MICROWAVE HEATED MILK

The impact of microwave cooking on the formation of early Maillard pro ducts was investigated and compared with the effect of conventional co oking, using milk as a test system. Experiments were carried out at co ntrolled temperatures of 80 degrees C and 90 degrees C, respectively, at holding times up to 420 min. Furosine, hydroxymethylfurfural (HMF) and lactulose, which are all established indicators to estimate heat d amage, were determined. The concentrations of all the heating indicato rs increased with increasing heating time. For example in the 90 degre es C test series the furosine values rose from 34 mg litre(-1) (0.5 h) to 94 mg litre(-1) (2 h holding time) in the milk heated by microwave s and from 35 mg litre(-1) (0.5 h) to 96 mg litre(-1) (2 h) in the con ventionally heated milk. None of the reaction products showed signific ant differences as between the microwave heating and conventional cook ing methods.