Loss of UHT milk quality: changes in compositional and physicochemical parameters triggered by different storage conditions

The objective of this study was to evaluate some compositional and physicochemical changes that occur during UHT (Ultra-high temperature) milk storage for up four months. A total 120 samples were collected from two dairy plants in the state Minas Gerais, Brazil, stored under temperatures (20°C 30°C) five periods (0, 30, 60, 90 days). experimental design completely randomized, a 2x2x5 factorial arrangement, with six replicates per treatment (six batches). Evaluated parameters included fat, protein, casein, lactose, solids, solids nonfat (SNF) urea nitrogen (MUN) contents, as well acidity, density, freezing point indexes lipolysis caseinomacropeptide (CMP). When compared Brazilian requirements milk, mean values ​​for fat SNF contents accordance standards ​​until last day storage. other are still not covered by specific legislation Brazil. There no change relative density lactose content also remained constant, except decrease at fourth month. significant increase, over time, MUN, CMP occurred. On hand, there protein contents. results showed gradual loss quality storage, aggravated rise temperature. These findings demonstrate could be improved adding such indexes.