Sucralose 3D Structure
Sucralose is an artificial sweetener known by the trade name Splenda. In the European Union, it is also known under the E number (additive code) E955. It is 320 - 1,000 times as sweet as sucrose, making it roughly twice as sweet as saccharin and four times as sweet as aspartame. It is manufactured by the selective chlorination of sucrose, by which three of sucrose's hydroxyl groups are substituted with chlorine atoms to produce 1,6-Dichloro-1,6-dideoxy-Î²- D-fructofuranosyl-4-chloro- 4-deoxy-Î±-D-galactopyranoside or C12H19Cl3O8. Unlike aspartame, it is stable under heat and over a broad range of pH conditions, and can be used in baking, or in products that require a longer shelf life.
Sucralose was discovered in 1976 by scientists from Tate & Lyle, working with researchers at Queen Elizabeth College (now part of King's College London). It was discovered by Leslie Hough and a young Indian chemist, Shashikant Phadnis. The duo was trying to test chlorinated sugars as chemical intermediates. On a late-summer day, Phadnis was told to test the powder. Phadnis thought that Hough asked him to taste it; so he did. He found the compound to be exceptionally sweet (the final formula was 600 times sweeter than sugar). They worked with Tate & Lyle for a year before settling down on the final formula.
It was first approved for use in Canada (marketed as Splenda) in 1991. Subsequent approvals came in Australia in 1993, in New Zealand in 1996, in the United States in 1998, and in the European Union in 2004. As of 2006, it has been approved in over 60 countries, including Brazil, China, India and Japan.
Tate & Lyle manufactures sucralose at a plant in McIntosh, Alabama, with additional capacity under construction in Jurong, Singapore. It is used in products such as candy, breakfast bars and soft drinks. Sucralose mixed with maltodextrin and dextrose (both made from corn) as a bulking agent is sold internationally by McNeil Nutritionals under the Splenda brand name. In the United States and Canada, this blend is increasingly found in restaurants in yellow packets, in contrast to the pink packets commonly used by saccharin sweeteners and the blue packets used by those containing aspartame; though in Canada yellow packets are also associated with the SugarTwin brand of cyclamate sweetener.
Most products that contain sucralose add bulking agents and additional sweetener to bring the product to the approximate volume and texture of an equivalent amount of sugar. This is because sucralose is nearly 600 times sweeter than sucrose (table sugar). Pure sucralose is sold in bulk, but not in quantities suitable for individual use. Pure dry sucralose undergoes some decomposition at elevated temperatures. When it is in solution or blended with maltodextrin it is slightly more stable.
Sucralose can be found in more than 4,500 food and beverage products. Sucralose is used as a replacement of, or in combination with other artificial sweeteners such as aspartame, acesulfame potassium or high-fructose corn syrup.
Sucralose is the most heat stable artificial sweetener available, allowing it to be used in many recipes without any use of sugar. Sucralose is available in granulated form so as to measure cup for cup like sugar.
If a recipe requires more than 1 cup of sugar, replacing it completely with sucralose usually will not work. However, sucralose is available blended with half sugar and half sucralose, so it may be used in such recipes, or ones requiring the ability to brown, raise, and activate yeast as sugar does.
Sucralose has been accepted by several national and international food safety regulatory bodies, including the U.S. Food and Drug Administration (FDA), Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives, The European Union's Scientific Committee on Food, Health Protection Branch of Health and Welfare Canada and Food Standards Australia-New Zealand (FSANZ). The acceptable daily intake for sucralose is 9 mg/kg of body weight per day. (Note that Splenda is mostly maltodextrin.)
"In determining the safety of sucralose, FDA reviewed data from more than 110 studies in humans and animals. Many of the studies were designed to identify possible toxic effects including carcinogenic, reproductive and neurological effects. No such effects were found, and FDA's approval is based on the finding that sucralose is safe for human consumption."
Concerns have also been raised about the effect of sucralose on the thymus gland, a gland that is important to the immune system. A report from NICNAS cites two studies on rats, both of which found "a significant decrease in mean thymus weight" at a certain dose. The sucralose dosages which caused the thymus gland effects referenced in the NICNAS report was 3000 mg/kg bw/day for 28 days. For an 80 kg (176 lb) human, this would mean a 28-day intake of 240 grams of sucralose, which is equivalent to more than 240 individual Splenda packets/day for approximately one month. The dose required to provoke any immunological response was 750 mg/kg bw/day, or 60 grams of sucralose, which is more than 60 Splenda packets/day. These and other studies were considered by regulators before concluding that sucralose was safe.
Chlorine atoms are covalently bonded to the carbon atoms in the sucralose molecule, making it a chlorocarbon. Many chlorocarbons are toxic; however, sucralose is unlike these chemicals because it is extremely insoluble in fat and does not accumulate in fat like most chlorinated hydrocarbons. In addition, sucralose does not break down or dechlorinate.
The bulk of sucralose ingested does not leave the GI tract and is directly excreted in the feces while 11-27% of it is absorbed. The amount that is absorbed from the GI tract is largely removed from the blood stream by the kidneys and excreted in the urine with 20-30% of the absorbed sucralose being metabolized. Sucralose is digestible by a number of microorganisms and is broken down once released into the environment.
Critics of sucralose often favor natural alternatives, including xylitol (birch sugar widely used during World War II), maltitol, thaumatin, isomalt (popular in some European countries), and the unapproved sweetener Stevia (widely used in Japan). In the US, Stevia can only be sold as a dietary supplement, not a sweetener, and it may not be sold at all in the UK.