Lactose is a simple carbohydrate found in milk. Another name for it is “milk sugar.” It is a reducing sugar which means it reacts with amino acids at high temperatures. This may determine the final flavor. Lactose has many uses in the food and pharmaceutical industries. In the food industry, its uses are based on its relative sweetness and being a source of energy. It is less sweet than sucrose, with up to 3.3 times the concentration of lactose being required to give the same level of sweetness as sucrose. This means that more lactose can be used without making the product too sweet. Lactose maintains the crystallized sugar texture without causing the food to become too sweet.

USES

Lactose also has a number of low-volume, special applications in the food industry, for example, as a free-flowing or agglomerating agent, to accentuate/enhance the flavor of some foods, to improve the functionality of shortenings, and as a diluent for pigments, flavors, or enzymes.

Lactose is used in the confectionary industry to produce caramel flavors through the Maillard reaction, usually with milk proteins, often added with the lactose in the form of sweetened condensed milk.

The Maillard reaction is also important for its use in the bakery industry where it is used to promote crust browning as the yeast used during the rising process cannot utilize lactose, leaving it as a reducing sugar available to undergo the browning reaction.

Lactose can also adsorb food dyes and flavors and it finds uses in confectionery where this property is exploited.

In the pharmaceutical industry, lactose is used as the main carrier (about 70% of tablets contain lactose) for drugs because it is not sweet, it is safe, it is available in highly refined form, and it makes good quality tablets. It has found uses in the industry in a number of different product forms.

The main one is α-lactose monohydrate, which can be used as a tablet excipient, but it can also be finely milled to produce inhaler-grade lactose. Here, the lactose acts as a carrier for micronized drug materials to reach the lungs. Both anhydrous lactose (β-lactose) and spray-dried lactose are also used to make tablets. The form of the lactose is critical for consistent tablet formulations, and much emphasis is placed on the reproducibility between batches of the particle properties that are required to produce consistent tablets, with an even spread of the active drug dispersed within the lactose powder being used as an excipient.