Process for producing lactose-free milk

Abstract

The invention concerns a process for producing lactose-free or substantially lactose-free milk, preferably without addition of water, and the product obtainable by the process. The process comprises the steps of: a) Ultrafiltration of original milk to obtain a first permeate and a first retentate; b) Nanofiltration of said first permeate to obtain a second permeate and a second retentate; c) Mixing said first retentate with said second permeate to obtain a mixture; and d) Hydrolysing remaining lactose in said mixture to obtain a hydrolysed milk. The process provides a lactose-free product with the taste of the original milk.

1 . A process for producing lactose-free or substantially lactose-free milk, comprising the steps of:
 a) Ultrafiltration of original milk to obtain a first permeate and a first retentate;   b) Nanofiltration of said first permeate to obtain a second permeate and a second retentate;   c) Mixing said first retentate with said second permeate to obtain a mixture; and   d) Hydrolysing remaining lactose in said mixture to obtain a hydrolysed milk.   
     
     
         2 . A process according to  claim 1 , wherein no water is added during the process. 
     
     
         3 . A process according to  claim 1  or  2 , wherein no minerals are added during the process. 
     
     
         4 . A process according to any of the preceding claims, wherein the pH of the process is within a range selected among the ranges 5.5-7.5; 6.0-7.0; 6.6-6.9; and 6.7-6.8; preferably wherein the pH is kept about the pH of the original milk. 
     
     
         5 . A process according to any of the preceding claims, wherein the process is conducted as a continuous process, and the concentration coefficient of step a) is a value in an interval selected among 1.8-2.2; and 1.9-2.1; preferably about 2.0. 
     
     
         6 . A process according to any of the preceding claims, wherein the process is conducted as a continuous process, and the concentration coefficient of step b) is a value in an interval selected among 3.5-4.7; 3.7-4.5; 3.8-4.4; 3.9-4.3; and 4.0-4.2; preferably about 4.1. 
     
     
         7 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of lactose in the obtained milk is less than a value selected among 0.50%; 0.45%; 0.40%; 0.35%; 0.30%; 0.25%; 0.20%; 0.19%; 0.18%; 0.17%; 0.16%; 0.15%; 0.14%; 0.13%; 0.12%; 0.11%; 0.10%; 0.09%; 0.08%; 0.07%; 0.06%; 0.05%; 0.04%; 0.03%; 0.02%; and 0.01%. 
     
     
         8 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of calcium in the obtained milk product is selected among 110-130 mg/100 g, 115-125 mg/100 g, and 118-122 mg/100 g, preferably about 120 mg/100 g milk. 
     
     
         9 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of protein in the obtained milk product is selected among 3.5-3.8%, 3.6-3.7% and about 3.7%; preferably about the protein concentration in the original milk, more preferred slightly higher. 
     
     
         10 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of chloride in the obtained milk product is selected among 88-90, 85-95, 80-100, and 75-105 mg/100 ml. 
     
     
         11 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of sodium in the obtained milk product is selected among 33-34, 32-35, 30-40, 25-45, and 20-50 mg/100 ml. 
     
     
         12 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of potassium in the obtained milk product is selected among 125-137, 126-134, 127-132, 128-130, and about 129 mg/100 ml. 
     
     
         13 . A process according to any of the preceding claims for obtaining a milk product, wherein the concentration of carbohydrate in the obtained milk product is selected among less than 3.4, preferably less than 3.3, more preferred less than 3.2, preferably less than 3.1, more preferred less than 3.0, preferably less than 2.9 g/100 ml. 
     
     
         14 . A milk product obtainable by the process according to any of the preceding claims. 
     
     
         15 . A milk product according to  claim 14 , wherein the coefficient of variation for finished milk products of the concentration of at least one, preferably all, of chloride, potassium, magnesium and sodium is less than 5%. 
     
     
         16 . A milk product according to  claim 14  or  15 , wherein the coefficient of variation for finished milk products of the concentration of at least one, preferably both, of ash and phosphorous is less than 5%. 
     
     
         17 . A milk product according to any of the  claims 14 - 16 , wherein the coefficient of variation for finished milk products of the concentration of at least one, preferably all, of calcium, enzymatic lactose, and protein is less than 5%. 
     
     
         18 . Use of a milk product according to any of the claims according to any of the  claims 14 - 17 , as a finished milk product without further processing steps, or to manufacture yoghurt, curd, quark or acidified milk products.