Effects of different components in skim milk on high-pressure-induced gelatinisation of waxy rice starch and normal rice starch

The gelatinisation of starch in skim milk required higher pressures than did the gelatinisation of starch in water. This study examined the effects of various milk components on the pressure-induced gelatinisation of waxy rice starch and normal rice starch, in order to understand the differences between the gelatinisation characteristics of starch in skim milk and starch in water. Gelatinisation was retarded in skim milk, which was attributed to the effects of soluble milk minerals and lactose. The presence of these components may reduce the plasticising ability of the suspension medium. Direct interactions between the milk components and starch molecules may also contribute to retarded gelatinisation. Milk proteins (casein and whey protein) did not affect the degree of pressure-induced gelatinisation at the concentrations of these components in skim milk, at 10% total solids. (C) 2008 Elsevier Ltd. All rights reserved.