Butter phase inversion

Phase inversion (Salager 1988 Salager et al. 2000 Salager et al. 2004) is used for preparation of some food products (e.g., production of margarine and butter), but is... 

Catastrophic phase inversion is used with products that naturally occur as oil-in-water emulsions, but are to be used as water-in-oil emulsions (butter, margarine). It is also an effective way of preparing emulsions with a dispersed phase that is high-viscous. However, the final droplet size is usually not very small, and the emulsion can be rather poly disperse. 

Phase Inversion Phase inversion is the process whereby a system changes from an oil-in-water emulsion to a water-in-oil emulsion, or vice versa (Figure 5). Phase inversion is an essential step in the manufacture of a number of important food products, including butter and margarine (1, 60, 85). In most other foods, phase inversion is undesirable because it has an adverse effect on the products appearance, texture, stability, and taste and should therefore be avoided. 

Butter is a water-in-oil emulsion (w/o emulsion) made Ifom cream by phase inversion occurring in the butter-making process. According to its manufacturing process, three types exist ... 

Mechanical agitation of the cream - a process called whipping - creates a metastable foam (i.e. it contains much air). Further whipping causes this foam to collapse some water separates out, and the major product is yellow butter. Incidentally, butter is a different form of colloid from milk, since its dispersed medium is water droplets and its dispersal phase is oil (milk is an oil-in-water colloid). Forming butter from milk is a simple example of emulsion inversion. 

The first step in systematic emulsion breaking is to characterize the emulsion to be broken in terms of its nature (OAV or W/O), the nature of the two phases, and the sensitivity of the emulsifiers. On the basis of such an evaluation, a chemical addition could be made to neutralize the effect of the emulsifier, followed by mechanical means to complete the phase separation. For example, butter results from the creaming, breaking, and inversion of emulsified droplets in milk. 

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