Process for the production of UHT milk with improved taste characteristics

Abstract

Suggested is a process for the production of a UHT milk with improved taste characteristics, comprising the following steps: (a) providing a raw milk; (b) separating the raw milk into a skimmed milk fraction and a cream fraction; (c) microfiltration or diafiltration of the skimmed milk fraction, obtaining a casein-containing retentate R1 and a fine whey as permeate P1; (d) ultrafiltration of the fine whey of step (c), obtaining a permeate P2 that is rich in lactose and minerals, and a protein-rich retentate R2; (e) mixing the cream fraction, the retentate R1 containing the casein and the permeate P2 containing the lactose and minerals, obtaining a mixed fraction M1; (f) ultra-high temperature treatment of the mixed fraction M1 of step (e); (g) pasteurization of the protein-rich retentate R2 obtained in step (d); and (h) mixing the ultra-heat treated fraction M1 of step (f) with the pasteurized retentate R2 of step (g), obtaining the target product.

Claims

1. A process for the production of a UHT milk with improved taste characteristics, comprising the following steps: (a) providing a raw milk; (b) separating the raw milk into a skimmed milk fraction and a cream fraction; (c) microfiltration or diafiltration of the skimmed milk fraction, obtaining a casein-containing retentate R1 and a fine whey as permeate P1; (d) ultrafiltration of the fine whey of step (c), obtaining a permeate P2 that is rich in lactose and minerals, and a protein-rich retentate R2; (e) mixing the cream fraction, the retentate R1 containing the casein and the permeate P2 containing the lactose and minerals, obtaining a mixed fraction M1; (f) ultra-high temperature treatment of the mixed fraction M1 of step; (e); (g) pasteurization of the protein-rich retentate R2 obtained in step (d); and (h) mixing the ultra-heat treated fraction M1 of step (f) with the pasteurized retentate R2 of step (g), obtaining the target product.

2. The process of claim 1, wherein separation is performed under hot conditions at a temperature in the range from about 20 to about 60 C.

3. The process of claim 1, wherein separation is performed under cold conditions at a temperature in the range from about 8 to about 18 C.

4. The process of claim 1, wherein microfiltration or diafiltration is performed with a membrane having an average pore size from about 0.1 to about 1 m.

5. The process of claim 1, wherein microfiltration or diafiltration is performed at a temperature in the range from about 10 to about 60 C.

6. The process of claim 1, wherein ultrafiltration is performed with a membrane having an average pore size from about 1,000 to about 5,000 nm.

7. The process of claim 1, wherein ultrafiltration is performed at a temperature in the range from about 10 to about 60 C.

8. The process of claim 1, wherein ultra-high temperature treatment is performed for a period from about 1 to about 10 seconds at a temperature in the range from about 100 to about 145 C.

9. The process of claim 1, wherein pasteurisation is performed for a period from about 10 to about 20 seconds at a temperature in the range from about 70 to about 75 C.

10. The process of claim 1, wherein the UHT milk with improved taste characteristics is converted to a dry powder after mixing in step (h).

Description

EXAMPLES

Example 1

(1) Solids were removed from 330 kg of pre-cooled raw milk in a separator at 8 C., which was then skimmed. In this process, 300 kg of skimmed milk and 30 kg of cream were obtained, which was subsequently pasteurised by ultra-high temperature treatment and further processed.

(2) The skimmed milk was heated to about 55 C. and then supplied to a microfiltration unit, into which it was placed together with 100 kg diafiltration water through a membrane with an average pore size of 0.1 m. 66 kg of retentate were obtained, which was 90% casein and also contained the complete amount of glycomacropeptides (GMP) and germs.

(3) 333 kg of fine whey were obtained as permeate, which had a dry matter content of about 5.5% by weight. The permeate was introduced into an ultrafiltration unit and applied through a membrane with an average pore size of 1,500 nm. 300 kg of permeate were obtained, which contained the lactose and the minerals, as well as 33 kg of permeate, in which the proteins appeared in concentrated form.

(4) The cream fraction and the first retentate and the second permeate were combined. As this fraction practically exclusively consisted of lipids, casein, lactose and minerals and did not contain any proteins, it could be subjected to a UHT treatment (3 seconds, 115 C.) without that a Maillard reaction was performed. In addition, these conditions were sufficient to destroy all germs contained in the first retentate.

(5) The protein fraction, i.e., the second retentate, was pasteurised under standard conditions (25 seconds, 74 C.). As this fraction did not contain any lactose, also in this case no Maillard reaction was performed.

(6) Finally, both fractions were mixed. A UHT milk with a high storage stability was obtained whose taste was barely distinguishable from raw milk.

Example 2

(7) The UHT milk of example 1 was applied to a spray tower and processed to a dry powder at an inlet temperature of 150 C. and an outlet temperature of 105 C., which still had a residual moisture of 2% by weight.