Lactose is a disaccharide also called milk sugar found in nature only in milk. It is the most important carbohydrate in milk. It has an important share in the aroma of milk. Lactose, a disaccharide composed of glucose and galactose, has an average ratio of 4.8% in cow’s milk and 7% in breast milk. It is found as 4.6% in sheep milk and 4.0% in goat milk. Since lactose participates in the osmotic system with mineral substances, the ratio of this milk component varies greatly in milk. In breast disorders, the lactose ratio in the milk obtained decreases more or less. Colostrum milk is still very low on the first day.
As a result of drying milk by heat treatment, only solid substances remain in it and this is called milk powder. Thanks to the drying process, it has a longer shelf life than other dairy products and its storage-storage method is easier than other dairy products.
Milk powder is usually produced using spray dryers, preferably skimmed or skimmed milk. Pasteurized milk is thickened until 50% solid matter remains in the evaporators. The thickened milk is pulverized in spray dryers.
Milk can also be dried, preferably in drum dryers. Milk powder can be obtained by pouring milk on heated drums and scraping off the solids in the dried milk with a knife. However, this process leaves undesirable effects on the taste (burning taste) and color (a darker color) of the milk powder.
Freeze-drying can also be used to obtain milk powder. While this process preserves the nutritional value of milk more than the drum dryer, it is not preferred due to the cost of the system used.