Compared to sucrose, relatively small quantities of lactose are produced worldwide. Lactose is produced by concentrating whey (a by-product of casein and cheese manufacture) or ultrafiltration permeate by vacuum concentration followed by crystallization of lactose from the concentrate, and recovery and drying of the crystals. An alternative method for lactose preparation is the Steffen process (precipitation with Ca(OH)2).
Applications of lactose in the food industry include in the manufacture of infant formulae (human milk contains more lactose than cows’ milk and hence cows’ milk-based infant formulae must be supplemented with lactose). Lactose has a low sweetness compared with other sugars. However, if properly crystallized, it has a low hygroscopicity which makes it suitable for certain uses in icing on confectionary products. Lactose is also used in the pharmaceutical industry as a diluent for tableting drugs (i.e., the small amount of active ingredient is “diluted” with lactose to make a sufficiently large tablet) and as a flavour adsorbent.