Whey has a fairly high salt content; about 8-12% calculated on Dry matter basis, its usefulness as an ingredient in human food is limited. Whey is demineralized partially (30-50%) and highly (90-95%). Demineralization involves removal of inorganic salts together with some reduction in the content of organic ions such as lactates and citrates.
Partial demineralization of whey is done through Nanofiltration membrane and high demineralization through Nanofiltartion membrane and Ion exchange resins.
Partially demineralized whey concentrate can be used in Ice cream and Bakery products and highly demineralized whey concentrate powder can be used in formulas for Infant food. Whey Protein Concentrate Powder and Lactose: Whey protein concentrates are powder made by drying the retentate from the Ultra Filtration of whey. They are described in terms of their protein content, % protein in dry matter basis, ranging from 35% to 85%. The concentration of whey proteins is primarily achieved by UF and Diafiltration.
The permeate of UF membrane is high in lactose content, so that is used for manufacturing lactose powder. Permeate recovered is concentrated to minimum 62% TS level in an evaporator and then cooled under controlled conditions for Lactose crystallization. Crystals are washed, decanted and dried to produce pharma grade lactose.