Partial Coalescence and Structure Formation in Dairy Emulsions

Abstract

The process of controlled partial coalescence of an emulsion during whipping and air incorporation is responsible for the establishment of structure in two notable dairy products, whipped cream and ice cream, leading to complex products described both as protein-stabilized emulsions and fat-stabilized foams. This process has been studied by several researchers in whipped cream (Schmidt and van Hooydonk, 1980; Walstra and Jenness, 1984; Brooker et al., 1986; Noda and Shiinoki, 1986; Anderson et al., 1987; Bruhn and Bruhn, 1988; Brooker, 1990; Needs and Huitson, 1991; Stanley et al., 1996) and ice cream (Govin and Leeder, 1971; Lin and Leeder, 1974; Goff and Jordan, 1989; Berger, 1990; Gelin et al., 1994; Kokubo et al., 1994). Partial coalescence is also responsible for structure formation in a variety of whipped non-dairy dessert toppings (Buchheim et al., 1985; Barfod and Krog, 1987; Krog et al., 1987). In 1988, Prof. John Kinsella co-supervised a Ph.D. dissertation prepared by myself on the topic of protein-emulsifier interactions at the fat globule interface and its relation to partial coalescence and structure formation in ice cream (Goff, 1988). This paper briefly reviews the topic of partial coalescence and describes further work completed by our research group at the University of Guelph since the completion of that dissertation. Prof. Kinsella is thus responsible for stimulating interest in this subject, which is an ongoing part of active research at present.