title: COLLOIDAL STABILITY OF ICE CREAM MIX.
abstract: The contributions of oil globule size (dv), emulsifying agent, hydrocolloid stabilizer, and temperature, to the stability of ice cream mix have been investigated. On ageing the mix at 20°C, the oil globules coalesce in one or two stages, depending on the initial size. When this is less than approximately 0.95 n, coalescence proceeds rapidly until a critical size is reached. The number of oil globules per unit volume of mix (TV) and variations in holding temperature influence the rate of coalescence at this stage. Subsequent coalescence, which is unaffected by N, proceeds at a much slower rate. Mixes with initial globule sizes exceeding 0.95 μ show only this second stage. It is suggested that the sharp reduction in coalescence rate for globules of diameter greater than 0.95 μ arises from the pronounced increase in the energy barrier to coalescence. Decreasing inter-facial area with increasing diameter of the globules leads to a more rigid emulsifier layer at the oil-water interface. Milk protein is the main contributor to stability during slow coalescence. The emulsifier exerts only a synergistic effect. Data are provided to show how the texture of frozen ice cream may be related to the initial size of the globules in the mix from which it is prepared.
authors.affiliation: Unilever Research, Welwyn, Herts, England.
authors.forename: P
authors.initials: P
authors.lastname: Sherman