1. Commonly table sugar or sucrose, which is extracted from the sugar beet or sugar cane, concentrated, and refined. Molasses is the residue left after the first stage of crystallization and is bitter and black. The residue from the second stage is treacle, less bitter and viscous than molasses. The first crude crystals are Muscovado or Barbados sugar, brown and sticky. The next stage is light brown, Demerara sugar. Refined white sugar is essentially 100% pure sucrose; technically described as semi-white, white, and extra-white (EU definitions). Yields 16 kJ (3.9) kcal/g. Soft sugars are fine-grained and moister, white or brown (excluding large-grained Demerara sugar).
2. Chemically a group of compounds of carbon, hydrogen, and oxygen (carbohydrates). The simplest sugars are monosaccharides. They may contain three (triose), four (tetrose), five (pentose), six (hexose), or seven (heptose) carbon atoms, with hydrogen and oxygen in the ratio CnH2nOn. The nutritionally important monosaccharides are hexoses: glucose (grape sugar), fructose (fruit sugar), and galactose. Two pentoses are also important: ribose and deoxyribose. See also disaccharides; oligosaccharides.
