Lactose and some of its derivatives

Lactose or milk sugar is the characteristic carbohydrate of milk and is the only sugar of animal origin. Lactose is a di‐saccharide of glucose plus galactose and is found in the three forms α‐lactose‐monohydrate, β‐lactose‐anhydride and amorphous lactose. β‐lactose in its stable and available non‐hygroscopic form is the commercial form of lactose. Lactose finds increasing applications as an excipient in pharmaceuticals, baby food, confectionery and many food recipes. Enzymatically hydrolysed lactose, especially in whey or whey derivatives, becomes increasingly interesting owing to its higher sweetness, functionality in toffee and ice cream and application in foods for people with lactose malabsorption. Lactitol, a new reduced‐calorie sweetener, is a sugar alcohol derived from lactose. Lactitol does not affect the blood glucose nor the insulin content, so it is a valuable sugar for diabetics. Lactitol is non‐cariogenic. Lactulose, a di‐saccharide of galactose and fructose, finds application in infant nutrition and medicine. The presence of lactulose in infant formula encourages the development of Bacterium bifidum in the intestinal flora. A medical use is the treatment of portal systemic encephalopathy and chronic constipation.