Behaviour of casein micelles at conditions comparable to those in ice cream

The structure and stability of the casein micelle are fairly well known und er conditions as in milk. However, much less is known and understood for co nditions as are prevalent in ice cream. In this study it was observed that structure and behaviour of casein micelles in ice cream plasma at - 10 degr ees C did not differ greatly from casein micelles in milk. A slightly incre ased amount of salts was associated with the micelles in ice cream plasma. Electron microscropy showed that casein in ice cream plasma exists in the f orm of micelles and submicelles. However, compared to milk, fewer submicell es and small micelles were present. Since the voluminosity was about the sa me as in milk, it was concluded that the increase in micelle size was prima rily caused by the fusion of micelles and not by swelling. The properties o f the casein micelles in ice cream plasma could be explained by a combinati on of the two conditions which differ significantly from those in milk: hig h concentration of milk components and low temperature. (C) 1999 Elsevier S cience Ltd. All rights reserved.