Abstract:

Both hydrophobic emulsifiers and submicronial fat particles are needed to stabilize water-in-vegetable oil emulsions. Polyglycerol polyricinoleate (PGPR) is superior to glycerol monooleate and/or lecithin, but is incapable of stabilizing fluid emulsions for sufficient storage periods. Fluid emulsions, unlike margarine, exhibit high droplet mobility and are susceptible to flocculation and coalescence. Submicronial $\alpha$-form crystals of hydrogenated fat can be obtained in the oil phase by the flash-cooling process. The crystals are homogeneously almost mono-dispersed and exhibit insufficient stability against flocculation and phase sepn. The use of an emulsifier (PGPR) in the fat crystn. process was very helpful in decreasing the aggregation and flocculation processes. The $\alpha$-form (mixed with $\beta$'-form) submicronial crystals can stabilize water-in-oil emulsions only in the presence of food emulsifiers, provided the concn. of tristearin is limited to 1.0-2.0 wt% (to prevent phase sepn. and high viscosity) and the PGPR is added at sufficient concns. (PGPR/tristearin ratio of 2.0 or more). Ideally stable (for over 6-8 wk) fluid emulsions can be formed in systems composed of fat submicrocryst. hydrophilic particles and food-grade emulsifiers. These water-in-oil emulsions can serve as the basic prepn. for any food-grade water-in-oil-in-water double emulsion. [on SciFinder(R)]