Sucralose is an artificial sweetener. The majority of ingested sucralose is not broken down by the body, so it is noncaloric. In the European Union, it is also known under the E number (additive code) E955. Sucralose is approximately 320 to 1,000 times as sweet as sucrose (table sugar), twice as sweet as saccharin, and three times as sweet as aspartame. It is stable under heat and over a broad range of pH conditions. Therefore, it can be used in baking or in products that require a longer shelf life. The commercial success of sucralose-based products stems from its favorable comparison to other low-calorie sweeteners in terms of taste, stability, and safety. Common brand names of sucralose-based sweeteners are Splenda, Sukrana, SucraPlus, Candys, Cukren and Nevella.
Sucralose was discovered in 1976 by scientists from Tate & Lyle, working with researchers Leslie Hough and Shashikant Phadnis at Queen Elizabeth College (now part of King’s College London). While researching ways to use sucrose and its synthetic derivatives, Phadnis was told to test a chlorinated sugar compound. Phadnis thought Hough asked him to “taste” it, so he did. He found the compound to be exceptionally sweet.
Tate & Lyle patented the substance in 1976; as of 2008, the only remaining patents concern specific manufacturing processes.
Sucralose was first approved for use in Canada 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. By 2008, it had been approved in over 80 countries, including Mexico, Brazil, China, India and Japan. In 2006, the Food and Drug Administration amended the regulations for foods to include sucralose as a non-nutritive sweetener in food. In May 2008, Fusion Nutraceuticals launched a generic product to the market, using Tate & Lyle patents.
Tate & Lyle currently manufactures sucralose both at a plant in Jurong, Singapore and at a recently reopened plant in McIntosh, Alabama. It is manufactured by the selective chlorination of sucrose (table sugar), which substitutes three of the hydroxyl groups with chlorine. This chlorination is achieved by selective protection of the primary alcohol groups followed by acetylation and then deprotection of the primary alcohol groups. Following an induced acetyl migration on one of the hydroxyl groups, the partially acetylated sugar is then chlorinated with a chlorinating agent such asphosphorus oxychloride, followed by removal of the acetyl groups to give sucralose.
Sucralose is found in many food and beverage products, used because it is a no-calorie sweetener, does not promote dental cavities, is safe for consumption by diabetics, and does not affect insulin levels. Sucralose is used as a replacement for, or in combination with, other artificial or natural sweeteners such as aspartame, acesulfame potassium or high-fructose corn syrup. Sucralose is used in products such as candy, breakfast bars and soft drinks. It is also used in canned fruits wherein water and sucralose take the place of much higher calorie corn syrup-based additives. Sucralose mixed withmaltodextrin or dextrose (both made from corn) as bulking agents is sold internationally by McNeil Nutritionals under the Splenda brand name. In the United States and Canada, this blend is increasingly found in restaurants, including McDonald’s, Tim Hortons and Starbucks, in yellow packets, in contrast to the blue packets commonly used by aspartame and the pink packets used by those containing saccharinsweeteners; in Canada, though, yellow packets are also associated with the SugarTwin brand of cyclamatesweetener.
Sucralose is a highly heat-stable artificial sweetener, allowing it to be used in many recipes with little or no sugar. It is available in a granulated form that allows for same-volume substitution with sugar. This mix of granulated sucralose includes fillers, all of which rapidly dissolve in liquids. While the granulated sucralose provides apparent volume-for-volume sweetness, the texture in baked products may be noticeably different. Sucralose is not hygroscopic, meaning it does not attract moisture, which can lead to baked goods that are noticeably drier and manifesting a less dense texture than those made with sucrose. Unlike sucrose, which melts when baked at high temperatures, sucralose maintains its granular structure when subjected to dry, high heat (e.g., in a 350 °F or 180 °C oven). Furthermore, in its pure state, sucralose begins to decompose into other substances at temperatures above 119 °C or 246 °F. Thus, in some baking recipes, such ascrème brûlée, which require sugar sprinkled on top to partially or fully melt and crystallize, substituting sucralose will not result in the same surface texture, crispness, or crystalline structure.
Packaging and storage
Pure sucralose is sold in bulk, but not in quantities suitable for individual use, although some highly concentrated sucralose-water blends are available online, using 1/4 teaspoon per one cup of sweetness or roughly one partsucralose to two parts water. Pure, dry sucralose undergoes some decomposition at elevated temperatures. In solution or blended with maltodextrin, it is slightly more stable. Most products containing sucralose add fillers and additional sweetener to bring the product to the approximate volume and texture of an equivalent amount of sugar.
Effect on caloric content
Though sucralose itself contains no calories, products that contain fillers, such as maltodextrin and/or dextrose, add about 2-4 calories per teaspoon or individual packet, depending on the product, the fillers used, brand, and the intended use of the product. The US Food and Drug Administration (FDA) allows for any product containing fewer than five calories per serving to be labeled as “zero calories”.
Health safety and regulation
Sucralose has been accepted by several national and international food safety regulatory bodies, including the 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). Sucralose is classed under “Caution” category by the consumer advocacy group Center for Science in the Public Interest, with the note “May pose a risk and needs to be better tested. Try to avoid”. According to the Canadian Diabetes Association, the amount of sucralose that can be consumed on a daily basis over a person’s lifetime without any adverse effects is 9 milligrams per kilogram of body weight.
“In determining the safety of sucralose, the 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.” For example, McNeil Nutritional LLC studies submitted as part of its U.S. FDA Food Additive Petition 7A3987 indicated that “in the 2-year rodentbioassays … there was no evidence of carcinogenic activity for either sucralose or its hydrolysis products …”
Results from over 100 animal and clinical studies in the FDA approval process unanimously indicated a lack of risk associated with sucralose intake. However, some adverse effects were seen at doses that significantly exceeded the estimated daily intake (EDI), which is 1.1 mg/kg/day. When the EDI is compared to the intake at which adverse effects are seen—known as the highest no adverse effects limit (HNEL)—at 1500 mg/kg/day, there is a large margin of safety. The bulk of sucralose ingested is not absorbed by the gastrointestinal (GI) tract and is directly excreted in the feces, while 11–27% of it is absorbed. The amount absorbed from the GI tract is largely removed from the blood stream by the kidneys and eliminated in the urine, with 20–30% of the absorbed sucralose being metabolized.
According to one study, sucralose is digestible by a number of microorganisms and is broken down once released into the environment. However, measurements by the Swedish Environmental Research Institute have shown wastewater treatment has little effect on sucralose, which is present in wastewater effluents at levels of several μg/l (ppb). There are no known ecotoxicological effects at such levels, but theSwedish Environmental Protection Agency warns there may be a continuous increase in levels if the compound is only slowly degraded in nature.
Other potential effects
A Duke University study funded by the Sugar Association found evidence that doses of Splenda of between 100 and 1000 mg/kg, containing sucralose at 1.1 to 11 mg/kg (compare to the FDA Acceptable Daily Intake of 5 mg/kg), reduced the amount of fecal microflora in rats by up to 50%, increased the pH level in the intestines, contributed to increases in body weight, and increased levels of P-glycoprotein (P-gp). These effects have not been reported in humans. An expert panel, including scientists from Rutgers University, New York Medical College,Harvard School of Public Health, Columbia University, and Duke University reported in Regulatory Toxicology and Pharmacology that the Duke study was “not scientifically rigorous and is deficient in several critical areas that preclude reliable interpretation of the study results”. Another study linked large doses of sucralose, equivalent to 11,450 packets (136 g) per day in a person, to DNA damage in mice. In a small scale study of 17 obese test subjects, sucralose was found to affect glycemic and insulin responses, leading to an increase in peak plasma glucose concentration and insulin secretion rate.