Fructose, or fruit sugar, is a simple monosaccharide found in many foods. It is one of the three important dietary monosaccharides along with glucose and galactose. The organic fructose molecule was first discovered by Augustin-Pierre Dubrunfaut in 1847.Fructose is a white solid that dissolves in water – it is the most water-soluble of all the sugars.Honey, tree fruits, berries, melons, and some root vegetables contain significant amounts of molecular fructose, usually in combination with glucose, stored in the form of sucrose. About 240,000 tonnes of crystalline fructose are produced annually.
Molecular formula:C6H12O6
Food features:Fructose is a 6-carbon polyhydroxyketone. It is an isomer of glucose, i.e. both have the same molecular formula (C6H12O6), but they differ structurally. Crystalline fructose adopts a cyclic six-membered structure owing to the stability of its hemiketal and internal hydrogen-bonding. This form is formally called D-fructopyranose. In solution, fructose exists as an equilibrium mixture of 70% fructopyranose and about 22% fructofuranose, as well as small amounts of the three other forms, including the acylic structure.
Nutritional value:
Uses:Studies that have compared high-fructose corn syrup (an ingredient in nearly all soft drinks sold in the US) to sucrose (common table sugar) find that most measured physiological effects are equivalent. For instance, Melanson et al. (2006), studied the effects of HFCS and sucrose sweetened drinks on blood glucose, insulin, leptin, and ghrelin levels. They found no significant differences in any of these parameters.[50] This is not surprising, since sucrose is a disaccharide that digests to 50% fructose and 50% glucose, whereas the high-fructose corn syrup most commonly used on soft drinks is 55% fructose and 45% glucose. The difference between the two lies in the fact that HFCS contains little sucrose, the fructose and glucose being independent moieties. |