Sucralose

Sucralose (l,6-dichloro-l,6-dideoxy- 5-fructofuranosyl-4-chloro-a-D-galactopyra- noside) is a nonnutritive sweetener based on sucrose. It is selectively chlorinated and the glycoside link between the two rings is resistant to hydrolysis by acid or enzymes, so it is not metabohzed. It has 400 to 800 times the sweetness of sucrose, is very soluble in water, and is stable in heat. It can be used in food products that are baked or fried. 

Sucralose is produced by the selective chlorination of the sucrose molecule using a patented process by Tate and Lyle that replaces the three hydroxyl groups (OH) with three chlorine (Cl) atoms. 

This modified sugar is minimally absorbed by the body and passes out unchanged. It was approved for use in foods and beverages in 1999 in the United States. 

The sweetness quality of sucralose is similar to that of sucrose. Sucralose exhibits synergism with acesulfame K, cyclamate, saccharin and stevioside (Tate Lyle Pic, 1985a, 1986). It is not synergistic with sucrose and shows little sweetness intensity synergy with aspartame. However, the sweetness quality of sucralose can be improved in cola by blending with aspartame (Tate Lyle Pic, 1985b). 

Sucralose is not metabolised by mammalian species and is poorly absorbed by the body. JECFA has assigned an ADI of 15 mg/kg bw. Sucralose was approved in the United States in April 1998 for use in a variety of food applications, including soft drinks. In August 1999, this approval was extended to full-category GMP approval. In the United Kingdom, it was granted a temporary approval on 15 March 2002 (UK Statutory Instrument 379). In 2004, sucralose was added to the EU list of permitted sweeteners. 

To date, the use of sucralose in soft drinks in the markets in which it is approved has been relatively limited. There have been a number of launches in the United States involving small- to medium-sized brands. In the United Kingdom, at the time of writing, there are only a handful of relatively minor soft drinks that have converted to sucralose. 

Splenda TGS l, 4, 6 -trichlorogalactosucrose 4,l, 6 -tri-chloro-4,l, 6 -trideoxy-gu/ucto-sucrose. 

Sucralose is used as a sweetening agent in beverages, foods, and pharmaceutical applications. It has a sweetening power approximately 300-1000 times that of sucrose and has no aftertaste. It has no nutritional value, is noncariogenic, and produces no glycemic response. See also Table I. 

Sucralose is a white to off-white colored, free-flowing, crystalline powder. 

Melting point 130°C (for anhydrous crystalline form) 36.5°C (for pentahydrate). 

Solubility freely soluble in ethanol (95%), methanol, and water slightly soluble in ethyl acetate. 

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Sucralose has the structure most similar to su crose Galactose replaces the glucose unit of sucrose and chlorines replace three of the hydroxyl groups Sucralose is the newest artificial sweetener having been approved by the U S Food and Drug Adminis tration in 1998 The three chlorine substituents do not dimmish sweetness but do interfere with the ability of the body to metabolize sucralose It there fore has no food value and IS noncaloric... 

Saccharin sucralose and aspartame illustrate the diversity of structural types that taste sweet and the vitality and continuing development of the in dustry of which they are a part ... 

Other Sweeteners. Two other sweeteners, sucralose and cyclamates, are approved for use outside of the United States. Sucralose, a chlorinated derivative of sucrose which is 500—600 times as sweet as sugar, has received limited approval in Canada, and petitions for its approval are pending in the United States and Europe (71). Cyclamate sweeteners, once available in the United States, but now baimed because they caused bladder cancer in animals, are stiU available in Canada and Europe. Table 7 gives several examples of nonnutritive sweeteners that have been developed. 

Fmctose is sweeter than sucrose at low temperatures (- S C) at higher temperatures, the reverse is tme. At 40°C, they have equal sweetness, the result of a temperature-induced shift in the percentages of a- and P-fmctose anomers. The taste of sucrose is synergistic with high intensity sweeteners (eg, sucralose and aspartame) and can be enhanced or prolonged by substances like glycerol monostearate, lecithin, and maltol (19). 

A chlorination process (20,21,44—46) converts sucrose into sucralose [56038-13-2] (4,l, 6 -trichloro-4,l, 6 -trideoxy-galactosucrose), a heat-stable, noncariogenic, noncaloric, high intensity sweetener. Sucralose is approved for food use in Canada, Australia, and Russia. It is not yet approved for use in the United States. 

Trityl Ethers. Treatment of sucrose with four molar equivalents of chlorotriphenylmethyl chloride (trityl chloride) in pyridine gives, after acetylation and chromatography, 6,1, 6 -tri-O-tritylsucrose [35674-14-7] and 6,6 -di-O-tritylsucrose [35674-15-8] in 50 and 30% yield, respectively (16). Conventional acetylation of 6,1, 6 -tri-O-tritylsucrose, followed by detritylation and concomitant C-4 to C-6 acetyl migration using aqueous acetic acid, yields a pentaacetate, which on chlorination using thionyl chloride in pyridine and deacetylation produces 4,l, 6 -trichloro-4,l, 6 -trideoxygalactosucrose [56038-13-2] (sucralose), alow calorie sweetener (17). 

The sweetness of fmctose is enhanced by synergistic combiaations with sucrose (12) and high iatensity sweeteners (13), eg, aspartame, sacchatin, acesulfame K, and sucralose. Information on food appHcation is available (14,15). Fmctose also reduces the starch gelatinization temperature relative to sucrose ia baking appHcations (16—18). 

The reactive intermediate, (C2H3)2NCH2CH2C1 HCl, which is used to produce cationic starch, is made by the reaction of (C2H3)2NCH2CH20H with thionyl chloride. A synthetic sweetener (qv), sucralose [56038-13-2] is made by the reaction of sucrose or an acetate thereof with thionyl chloride to replace three hydroxy groups by chlorines (187,188). 

Saccharin imparts a sweetness that is pleasant at the onset but is followed by a lingering, bitter aftertaste. Sensitivity to this bitterness varies from person to person. At high concentration, however, most people can detect the rather unpleasant aftertaste. Saccharin is synergistic with other sweeteners of different chemical classes. For example, saccharin—cyclamate, saccharin—aspartame, saccharin—sucralose, and saccharin—aUtame combinations all exert synergy to various degrees. The blends, as a rule, exhibit less aftertaste than each of the component sweeteners by themselves. 

Sucralose. Sucralose [56038-13-2] is a trichlorodisaccharide sweetener developed by the British sugar company Tate Lyle during the 1970s (87—89). It was Hcensed to McNeil Specialty Products Company (a Johnson Johnson subsidiary) in the United States. A food additive petition was filed with the FDA in 1987 (90). As of December, 1996, the petition was still pending. Sucralose was approved for use as a sweetener by Canada in 1991, by Austraha, Mexico, and Russia in 1993, by Romania in 1994, and by New Zealand in 1996. 

The disaccharide stmcture of (12) (trade name SPLENDA) is emphasized by the manufacturer as responsible for a taste quaUty and time—intensity profile closer to that of sucrose than any other high potency sweetener. The sweetness potency at the 10% sucrose solution sweetness equivalence is between 450 and 500X, or about two and one-half times that of aspartame. When compared to a 2% sugar solution, the potency of sucralose can be as high as 750X. A moderate degree of synergy between sucralose and other nonnutritive (91) or nutritive (92) sweeteners has been reported. 

Sucralose is quite stable to heat over a wide range of pH. However, the pure white dry powder, when stored at high temperature, can discolor owing to release of small quantities of HCl. This can be remedied by blending it with maltodextrin (93) and other diluents. The commercial product can be a powder or a 25% concentrate in water, buffered at pH 4.4. The latter solution may be stored for up to one year at 40°C. At lower pH, there is minimal decomposition. For example, in a pH 3.0 cola carbonated soft drink stored at 40°C, there is less than 10% decomposition after six months. The degradation products are reported to be the respective chlorinated monosaccharides, 4-chloro-4-deoxy-galactose (13) and l,6-dichloro-l,6-dideoxy-fmctose (14) (94). 

To meet consumer demands, manufacturers are developing new nonnutritive sweeteners that more closely match the taste and mouthfeel of sucrose. There are several nonnutritive sweeteners currentiy pending FDA approval for use in soft drinks. They include sucralose [56038-13-2] aUtame [80863-62-3] encapsulated aspartame, cyclamates, and acesulfame-K [55589-62-3] also known as paUtinit. 

Substituent effect, additivity of, 570 electrophilic aromatic substitution and, 560-563 summary of. 569 Substitution reaction, 138 Substrate (enzyme), 1041 Succinic acid, structure of, 753 Sucralose, structure of. 1006 sweetness of, 1005 Sucrose, molecular model of. 999 specific rotation of, 296 structure of, 999 sweetness of, 1005 Sugar, complex, 974 d, 980 L, 980... 

Sucralose is the sugar sucrose with three of the hydroxyl groups replaced by chlorine atoms. In the process, the stereochemistry of the glucose half of the molecule is changed, making it more like galactose. 

Sucralose is six hundred times sweeter than sugar but has no calories. 

Sucralose is used in a wide variety of no-calorie and low-calorie foods, such as tabletop sweeteners, baked goods, desserts, toothpastes, mouthwashes, and diet drinks. 

The metabolic and pharmacokinetic profile of sucralose (this is a novel intense sweetener with a potency about 600 times that of sucrose) in human volunteers was studied by Roberts and coworkers [82]. Part of this study was realized using PLC in the following chromatographic system in which the stationary phase was silica gel and the mobile phase was ethyl acetate-methanol-water-concentrated ammonia (60 20 10 2, v/v). Separated substances were scraped off separately, suspended in methanol, and analyzed by filtration, scintillation counting, or enzymatic assay. It was shown that the characteristics of sucralose include poor absorption, rapid elimination, limited conjugative metabolism of the fraction absorbed, and lack of bio-accumulative potential. 

How can sucralose, an artificial sweetener made from sugar, contain no calories See p. 205. 

How Can Sucralose, an Artificial Sweetener Made from Sugar, Contain No Calories ... 

Did you know the average American consumes the equivalent of 20 teaspoons of sugar each day The non-nutritive sweetener industry is described as a billion-dollar industry with projections of even more rapid expansion in the next few years. What do chemists look for in their search for an ideal sweetener Consumers seek good-tasting, nontoxic, low-caloric sweeteners. Chemists in the sweetener industry add further demands an inexpensive, easy-to-synthesize product that is readily soluble in water and resists degradation by heat and light is of prime importance. The chemical structure of sucralose keeps the sweetener intact as it passes through the acidic environment of the stomach. Thus, sucralose is not... 

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