Chemical Alterations of Heat Treated Concentrated Skim Milk

Heat induced production of 5-Hydroxymethylfurfural and of the proteinbound pigments (melanoidines) in concentrated skim milk was studied.Under normal commercial sterilization conditions (F < 5), 5-Hydroxymethylfurfural concentration increased sharply with the heat intensity.Above F = 5, (overheating), slightly additional amounts were produced.In contrast, the amount of protein-bound pigments increased at a constant rate with heating intensity iu the whole range of F (F --.5 to 18).Thus, 5-Hydroxymethylfurfural determination provides a rapid method for estimating the intensity of the heat treatment for normal processing of concentrated milks.However, accurate measurement of overheating would require the more time-consuming determination of protein-bound pigments.