Process for preparing fat slurries and a process for preparing emulsions of such slurries
A process for the preparation of an edible fat slurry containing oil and solid fat particles of hardstock fat, in which said slurry is made by adding a melted hardstock fat to cold liquid oil in a vessel over a period of time. The invention also relates to a process for turning such slurry into an oil-continuous emulsion.
1. A process for preparing an emulsion comprising liquid edible oil and solid fat particles of hardstock fat, which process comprises the steps of:
a) providing a vessel comprising a liquid oil at a temperature of below 20° C.;
b) providing a melted hardstock fat at a temperature of above 35° C., wherein the hardstock fat is not a fat powder;
c) forming a fat slurry by adding at least a portion of the melted hardstock fat to the liquid oil in the vessel, gradually over a period of from 0.5 to 60 minutes, with continuous mixing, such that the concentration of hardstock fat in the liquid oil increases during said period from less than 10% to at least 90%; and
d) forming an emulsion by mixing the fat slurry with an aqueous phase;
wherein the temperature of the liquid oil and the temperature of the melted hardstock fat are chosen such that the temperature of the fat slurry remains below 20° C. during steps c); and
wherein the vessel is equipped with a recycle loop, and wherein the melted hardstock fat is added to the liquid oil in the recycle loop.
2. The process of claim 1 , wherein the process is carried out batchwise.
3. The process of claim 1 , wherein the liquid oil in the vessel in step a) prior to mixing with the melted hardstock fat is substantially free of water.
4. The process of claim 1 , wherein the melted hardstock fat is gradually added to the oil over a time interval of between 3 and 30 minutes.
5. The process of claim 1 , wherein the total amount of melted hardstock fat added to the liquid edible oil is from 1.5 to 40% by weight of the resulting fat slurry.
6. The process of claim 1 , wherein the temperature of the oil in the vessel in step a) is 2° C. or more to less than 20° C.
7. The process of claim 1 , wherein the temperature of the melted hardstock fat in step b) is greater than 35° C. to up to 80° C.
8. The process of claim 1 , wherein the temperature of the liquid oil and the temperature of the melted hardstock fat are chosen such that the temperature of the resulting fat slurry after addition of all of the hardstock fat is below 25° C.
9. The process of claim 1 , wherein the recycle loop is equipped with a mixer, and wherein the melted hardstock fat is added to the oil in the recycle loop in or upstream of the mixer.
10. The process of claim 9 , wherein the mixer is a dynamic in-line mixer.
11. The process of claim 1 , wherein the fat slurry contains 0.01 to 0.8% of a monoglyceride emulsifier by weight based on the slurry, and the monoglyceride emulsifier is mixed with the oil in step a).
12. The process of claim 1 , wherein the total amount of melted hardstock fat added to the liquid edible oil is from 3 to 30% by weight of the resulting fat slurry.
13. The process of claim 1 , wherein the temperature of the oil in the vessel in step a) is between 5 and 15° C.
14. The process of claim 1 , wherein the temperature of the melted hardstock fat in step b) is between 40 and 75° C.
15. The process of claim 1 , wherein the liquid oil in the vessel in step a) prior to mixing with the melted hardstock fat comprises less than 5% water.
16. The process of claim 1 , wherein the fat slurry does not contain fat powder.
17. The process of claim 1 , wherein the fat slurry is not formed from fat powder.
18. The process of claim 1 , wherein the temperature of the slurry is at least 20° C. below the melting point of the hardstock fat.