Predicting safety and quality parameters for UHT-processed milks

A spreadsheet was developed to evaluate safety and quality parameters for milks subjected to different heating and cooling profiles and holding time conditions in a continuous heat exchanger. Safety parameters evaluated were lethality ( Fo) and microbial inactivation ( B*) values; quality parameters were chemical change ( C*), thiamin loss, lactulose formation, Maillard browning and hydroxymethylfurfural (HMF) formation. The spreadsheet was used to predict these parameters for a pilot plant, heating milks at 120–150°C for 4, 27 and 58 s, using its heating and cooling profiles. Milks were processed in the same plant at these conditions and a selection of the milks were analysed to establish the validity of the spreadsheet. All samples with a C* value