Quality aspects of UHT cream
1996
Muir, D.D. (Hannah Research Inst., Ayr (UK)) | Kjaerbye, H.
UHT dairy creams fulfil a number of functions and the consumer expects creams of different fat content to behave in different ways. Broadly speaking, UHT creams with low fat content (12-18 per cent) are added to coffee whilst those with higher fat contents (35-48 per cent) are used as toppings to desserts. In both cases, it is anticipated that the cream should have no taint or off-flavour and that, during storage, changes in the physical properties of the cream should be minimal; that is, product should not thicken excessively nor should sedimentation or fat separation occur. In addition, creams for use in coffee should be stable in this hot acid environment whilst creams to be used as toppings should whip into a stable, light foam. Seasonal changes in milk composition can seriously influence the quality of UHT cream. In addition, recent evidence suggests that extra-cellular protease derived from psychrotrophic, Gram-negative bacteria can degrade the functionality of UHT cream. Whilst the effects on cream quality of degradative enzymes can only be ameliorated by assurance of high quality raw material, seasonal effects of milk composition can be moderated by judicious choice of processing conditions, product storage temperature, and by use of selected additives. Recent advances in the manufacture of modified creams have allowed the functional properties of UHT sterilized creams to be extended. Although the mechanisms underlying these changes in functionality are, for the present, poorly understood, careful use of additives substantially improves product functionality and storage stability.
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