Production of casein by passage through a duct with a constriction

Claim 2

A process according to claim 1, in which the milk is heated by injecting steam into a stream of the milk.

Claim 3

A process according to claim 1, in which before heating, the milk is destabilized with rennet at a temperature not higher than 10* C.

Claim 4

A process according to claim 1, in which the flow through the first duct before the constricted portion has a V.De value in the range 300 to 450 cm2 sec 1.

Claim 5

A process according to claim 1, in which the pasteurization temperature is in the range 65* to 80* C and the slurry is heated to pasteurization temperature by direct steam injection.

Claim 6

A process according to claim 1, in which the slurry is passed through the second duct at a V.De value of from 200 to 300 cm2 sec 1.

Claim 7

A process according to claim 1, in which the slurry is passed through the second constriction at a V.De value in the range 1000 to 1900 cm2 sec 1.

Claim 8

A process according to claim 1, in which the separated casein is mixed with an aqueous solution or suspension of an alkali, the pH of the mixture is adjusted to a value in the range 6 to 7 and the caseinate is recovered from the mixture.

Claim 9

An improved process for separating casein from skimmed milk wherein milk is destabilized, heated to from 40* to 60* C with agitation to produce a slurry of casein in lactoserum and passed through a first duct having a constricted portion to a region where pasteurization takes place, after which said casein is separated from said lactoserum, wherein the improvement comprises the steps of passing said slurry through said first duct before reaching said constricted portion at a flow rate having a V.De value of less than 600 cm2 sec 1, the residence time in said duct before reaching the constricted portion being from 30 to 60 seconds, and passing said slurry through said constriction at a flow rate having a V.De value of from 1000 to 1500 cm2 sec 1, V being the mean stream velocity and De being the hydraulic equivalent diameter of the duct at the point where measured.

Claim 10

An improved process for separating casein from skimmed milk wherein said milk is destabilized, heated to from 40* to 60* C with agitation to produce a slurry of casein in lactoserum, passed through a first duct having a constricted portion and passed through a second duct, after which the casein is separated from said lactoserum, wherein the improvement comprises passing the slurry through said first duct at a flow rate having a V.De of 300 to 350 cm2 sec 1, through said constriction at a flow rate having a V.De of 1000 to 1500 cm2 sec 1, and through said second duct at a flow rate having a V.De value not exceeding 400 cm2 sec 1, and the residence time of said slurry in said second duct being from 30 to 60 seconds, V being the streaming velocity of said slurry and De being the hydraulic equivalent of a duct at the point where measured.

Claim 11

An improved process for separating casein from skimmed milk wherein said milk is destabilized, heated to from 40* to 60* C with agitation to produce a slurry of casein in lactoserum, passed through a first duct having a first constricted portion and through a second duct having a second constricted portion, after which said casein is separated from said lactoserum, wherein the improvement comprises the steps of passing said slurry through said first duct before reaching said first constriction at a flow rate having a V.De of less than 600 cm2 sec 1, said slurry having a residence time in said first duct before reaching said first constriction of 30 to 60 seconds, through said first constriction at a flow rate having a V.De of 1000 to 1500 cm2 sec 1, through said second duct before reaching said second constriction at a V.De value of 200 to 300 cm2 sec 1, said slurry being simultaneously pasteurized, and through said second constriction at a flow rate having a V.De value of at least 900 cm2 sec 1, V being the mean streaming velocity of the slurry and De being the hydraulic equivalent diameter at the point where measured.