Fat Separation in Evaporated Milk. III. Gravity Separation and Heat Stability

Fat separation is a continuous problem in the production, handling, and storage of evaporated milk. This defect becomes most objectionable during prolonged quiescent storage at high temperatures. The butterfat rises to the upper surface forming a viscous, leathery layer, which may prevent pouring of the milk from a relatively small opening. To retard fat separation, the manufacturer attempts to obtain effective homogenization and sufficient coagulation of the proteins during sterilization to give the product a high viscosity or "heavy body" (1, 12, 14). These practical applications are aimed at three fundamental considerations: a reduction in the size of the fat globules, an increase in the viscosity of the suspending phase, and perhaps an alteration in the density difference between the fat globule mass and the suspending medium (6).