PROCESS FOR MAKING EDIBLE OIL-CONTINUOUS EMULSIONS
A process for making edible oil-continuous emulsions by mixing slurries of hardstock fat crystals in oil with an aqueous phase to form an emulsion followed by addition of a melted hardstock. More in particular, the oil-continuous emulsions are spreads or margarines.
1 . A process for making an edible oil-continuous emulsion, which emulsion comprises 15-65% by weight of the total emulsion of an aqueous phase, and 35-85% by weight of the total emulsion of a fat phase, said fat phase comprising a first hardstock fat, a second hardstock fat, and edible oil, said process comprising the steps of:
a) preparing a dispersion comprising edible oil and fat crystals, by mixing 65% to 98% by weight of the dispersion of edible oil with 2 to 35% by weight of the dispersion of first hardstock fat, wherein the fat crystals in the dispersion have an average crystal thickness of less than 50 nm at a temperature of between 15° and 20° C. as measured with small angle x-ray scattering;
b) providing an aqueous phase at a temperature of from 0 to 25° C.;
c) mixing the dispersion prepared in step a) with the aqueous phase prepared in step b) to form an emulsion;
d) mixing the emulsion prepared in step c) with 1-35% by weight based on the total fat phase, of said second hardstock fat, wherein the second hardstock fat is liquid and at a temperature of between 30 and 80° C. at the time of mixing.
2 . The process of claim 1 , wherein the dispersion of step a) is obtained by mixing crystallised particles of the first hardstock fat with the edible oil, which edible oil is at a temperature of below 30° C.
3 . The process of claim 2 , wherein the crystallised particles of the first hardstock fat are micronized fat particles prepared by supercritical melt micronisation of the first hardstock fat.
4 . The process of claim 1 , wherein the dispersion of step a) is obtained by mixing the first hardstock fat which is melted and at a temperature of between 30° C. and 80° C. with the edible oil at a temperature of between −10 and 25° C. under shear, wherein the amounts and temperatures are selected such that the temperature of the dispersion is below the melting point of the first hardstock fat.
5 . The process of claim 1 , wherein the dispersion of step a) is obtained by providing a mixture of the first hardstock fat and the edible oil at a temperature so that this complete mixture is liquid, followed by cooling down this mixture to a temperature of between 0 and 25° C., preferably such cooling down is in a scraped surface heat exchanger.
6 . The process of claim 1 , wherein after the addition of the second hardstock fat of step d. the mixture so-obtained is subjected to shear in such a way that the temperature of the mixture exiting this shear device is below 35° C.
7 . The process of claim 1 , wherein the first and the second hardstock fat are of the same composition.
8 . The process of claim 1 , wherein the first and the second hardstock fat are of different composition.
9 . The process of claim 1 , wherein the second hardstock comprises 10 to 100% by weight on the second hardstock of sterols, stanols, or esters of sterols or stanols.
10 . The process of claim 1 , wherein the first hardstock fat and the second hardstock fat have at least 50% solids at 20° C. and at least 25% solids at 30° C.
11 . The process of claim 1 , wherein the emulsion comprises 20-55% by weight on the total emulsion of an aqueous phase and 45-80% by weight on the total emulsion of a fat phase.
12 . The process of claim 1 , wherein the dispersion prepared in step a) has an amount of solids of between 1 and 25% prior to the mixing performed in step c).
13 . The process of claim 1 , wherein the mixing in step c) is performed by a shear device which produces an emulsion with a water droplet size D 3.3 of between 1 and 20 micron, preferably between 2 and 15 micron, more preferably between 2 and 10 micron, and wherein the temperature of the emulsion after said mixing step is below 28° C.