Double sugar

A disaccharide, also known as a disaccharide, is a saccharide compound composed of two monosaccharide molecules. Commonly found are sucrose, lactose and maltose. Sucrose is dehydrated and condensed by a molecule of glucose and a molecule of fructose. It can be extracted from sugar cane or sugar beet. It is the most commonly used sugar in human life. It is absorbed in the intestinal tract by hydrolysis of sucrase to monosaccharide. Lactose is obtained by dehydration condensation of a molecule of glucose and a molecule of galactose, which is absorbed by the lactase in the intestine by hydrolysis to a monosaccharide. Lactose is only found in animal or human milk. Milk contains 4% lactose and human milk contains 5.7%. Lactose has the least sweetness in disaccharides and is especially important for infant nutrition. It can also be used in athletes' high-sugar and high-energy liquid diets. Maltose is formed by dehydration condensation of two molecules of glucose and is a product of the germination of cereals. Malt, starch, and glycogen are hydrolyzed by amylase to form a small amount of maltose, and human saliva and pancreatic amylase hydrolyze food starch to form maltose. Maltose is hydrolyzed into two molecules of glucose in the intestinal fluid for maltase. The sweetness of maltose is about 1/3 of that of sucrose, tastes refreshing, and has no disadvantages of stimulating the gastric mucosa, and can be applied in athlete nutrition. Free maltose and cellobiose are not found in nature, the former being a partial hydrolysate of starch and the latter being a partial hydrolyzate of cellulose. Sucrose, lactose and maltose are good foods and are also used as industrial raw materials. Sucrose in medicine is often used as a raw material for the production of dextran. Lactose is used as an excipient or diluent for tablets, powders. The disaccharide is classified into a reduced maltose type disaccharide and a non-reducing trehalose type disaccharide. Maltose and lactose belong to the former category. Maltose is a hydrolyzate of starch composed of two glucose molecules, which are specifically present in human and animal milk, and consist of a molecule of glucose and a molecule of galactose. It belongs to the latter category, such as sucrose, which is formed by the condensation of a molecule of glucose and a molecule of fructose. In the digestive tract of animals, there are specific enzymes that break down disaccharides, such as maltase, lactase and sucrase.