This is the latest accepted revision, reviewed on 7 January 2022. This article is about the class of sweet-flavored substances used as food. For common table sugar, see Sucrose. For the South Korean granulated sugar, see Lump Sugar.
For Sultan Ibrahim’s consort, see Şivekar Sultan. Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Starch is a glucose polymer found in plants, and is the most abundant source of energy in human food. Sugars are found in the tissues of most plants. Honey and fruit are abundant natural sources of simple sugars. Sucrose is especially concentrated in sugarcane and sugar beet, making them ideal for efficient commercial extraction to make refined sugar.
As sugar consumption grew in the latter part of the 20th century, researchers began to examine whether a diet high in sugar, especially refined sugar, was damaging to human health. The etymology reflects the spread of the commodity. Persian shakar, then to 12th century French sucre and the English sugar. The English word jaggery, a coarse brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin: Portuguese jágara from the Malayalam cakkarā, which is from the Sanskrit śarkarā. Sugar has been produced in the Indian subcontinent since ancient times and its cultivation spread from there into modern-day Afghanistan through the Khyber Pass. Different species seem to have originated from different locations with Saccharum barberi originating in India and S. Ikṣu and the sugarcane juice is known as Phāṇita.
They each exist as several isomers with dextro- and laevo-rotatory forms that cause polarized light to diverge to the right or the left. Fructose, or fruit sugar, occurs naturally in fruits, some root vegetables, cane sugar and honey and is the sweetest of the sugars. It is one of the components of sucrose or table sugar. Galactose generally does not occur in the free state but is a constituent with glucose of the disaccharide lactose or milk sugar. It is less sweet than glucose. It is a component of the antigens found on the surface of red blood cells that determine blood groups. Glucose occurs naturally in fruits and plant juices and is the primary product of photosynthesis.
Starch is converted into glucose during digestion, and glucose is the form of sugar that is transported around the bodies of animals in the bloodstream. Lactose, maltose, and sucrose are all compound sugars, disaccharides, with the general formula C12H22O11. They are formed by the combination of two monosaccharide molecules with the exclusion of a molecule of water. Lactose is the naturally occurring sugar found in milk. A molecule of lactose is formed by the combination of a molecule of galactose with a molecule of glucose.