Methods for heat treatment of milk
A process for producing a concentrated, sterilized liquid milk product comprising the steps of (a) partially concentrating milk or a milk product, and (b) sterilizing a partially concentrated milk product.
1. A process for producing a concentrated and sterilized milk product comprising the steps of:
(a) performing a concentration process by reverse osmosis on a starting material comprising milk or a milk product and forming a more concentrated milk product, wherein, the concentration process is performed at a temperature of no greater than 45° F. using a membrane having a molecular weight cut-off of 100 Da, wherein the starting material is subjected to a pressure of 450 psi to 1500 psi, and further wherein the concentration process removes water from the starting material; and
(b) performing a sterilization process on said more concentrated milk product by heating, wherein the sterilization process comprises a first heating step that heats the more concentrated milk product from a temperature of about 45° F. to a first elevated temperature between 175° F. to 177° F. within 45 seconds.
2. A process according to claim 1 , wherein the volume of the more concentrated milk product is 50% of the volume of the starting material.
3. A process according to claim 1 , wherein the milk is whole milk or skim milk.
4. A process according to claim 1 , further comprising the step of adjusting the total solids content of the more concentrated milk product prior to step (b).
5. A process according to claim 1 , wherein the more concentrated milk product comprises from 20 to 25% w/w of solids-not-fat (SNF).
6. A process according to claim 1 , further comprising a second heating step that heats the more concentrated milk product from the first elevated temperature to a second elevated temperature.
7. A process according to claim 6 , wherein said second heating step is carried out in under 5 seconds at a second elevated temperature ranging between 283° F. to 288° F.
8. A process according to claim 7 , further comprising a holding step, wherein the more concentrated milk product is maintained at the second elevated temperature for at least 4 seconds.
9. A process according to claim 8 , further comprising a cooling step, wherein the more concentrated milk product is subjected to an evaporation process.