Process for the preparation of lactose-free and reduced phosphorus skim milk

A method of preparing Lactose-free and Phosphorus-reduced milk comprising the steps of:

• providing skim milk;
• pasteurizing the skim milk;
• pre-cooling the skim milk to between about 5° C. to about 9° C.;
• pre-filtering the skim milk with a filter having pore sizes from about 30 to about 40 microns to remove any suspended solids to form pre-filtered, pasteurized skim milk;
• cooling the pre-filtered, pasteurized skim milk to about 4° C.;
• separating solid and liquid phases of the pre-filtered, pasteurized skim milk with Ultra-Centrifugation to produce a solid phase comprising Casein Micelles, Fat Globules and Globular Proteins and a liquid phase comprising water, dissolved sugars, minerals and lipoprotein particles;
• collecting and storing the solid phase in a stainless-steel tank;
• pumping the liquid phase into a feed section of an Ultra-Filtration unit;
• filtering the liquid phase by passing it through a filter secured in the Ultra-Filtration unit, wherein the filter has a plurality of pores having pore sizes ranging from about 0.5 microns to about 40 microns, and wherein a portion of Lactose and a portion of minerals present in the liquid phase are filtered out to form a filtered liquid phase;
• cooling the filtered liquid phase to between about 5° C. and 7° C.;
• bubbling CO2 into the filtered liquid phase to reduce the pH to from about 4.5 to about 5.0 to cause any Lactose present to form into Lactose crystals and to form a CO2 infused filtered liquid phase;
• returning the CO2 infused filtered liquid phase to the pre-filter;
• passing the CO2 infused filtered liquid phase through the pre-filter to remove any Lactose crystals present to form a lactose-free, CO2 infused filtered liquid phase;
• recombining the solid phase with the lactose-free, CO2 infused filtered liquid phase in the stainless-steel tank to form Lactose-free skim milk;
• heating or cooling the Lactose-free skim milk to about 65° F.;
• bubbling CO2 gas into the Lactose-free skim milk until a pH of from about 4.5 to about 4.6 is reached;
• coagulating a casein component in the Lactose-free skim milk to form coagulated skim milk;
• filtering the coagulated skim milk by passing it through a filter having pores, wherein each pore has a size of about 40 microns to separate the coagulated casein as retentate and liquid serum as permeate;
• adding calcium chloride to the permeate;
• adjusting the pH of the permeate to from about 6.5 to about 7.0 with a base to form a white crystalline precipitate of calcium phosphate in the permeate;
• filtering the permeate in an Ultra-Filtration unit to separate the calcium phosphate from the permeate to form a Phosphorus-reduced serum;
• and,
• mixing the casein retentate with the Phosphorus-reduced serum to form Lactose-free, Phosphorus-reduced skim milk.