Sweeteners, low-calorie

Aspartame is a low-calorie sweetener used in many foods and drinks. Because it is between 160 and 200 times sweeter than sugar, only very small amounts are needed to sweeten a product. A typical 12-ounce low-calorie soft drink will have 180 milligrams of aspartame in it. 

The artificial sweetener aspartame is the low-calorie sweetener of choice at the time of this writing, having replaced cycla-... 

In 1993, the di-D-fructose dianhydrides were summarized as being of little, if any, commercial importance. 73 However, a search of the literature reveals an appreciable number of patents issued since 1989 for the manufacture of these compounds. These include enzymic methods for the production of individual dianhydrides (Ref. 130) or methods of production of mixtures using anhydrous HF or pyridinium poly(hydrogen fluoride) (see Ref. 131). Most cite the di-D-fructose dianhydrides as low-calorie sweetening agents (Ref. 132), and some claim anti-cariogenic properties (Refs. 132 and 133). 

Low-Calories Sweeteners Sucralose. http //www.caloriecontrol.org/sucralos.html... 

Low-antimony lead alloys, 14 770 Low-birefringence polycarbonates, 19 822 Low-blush copolymers, 26 538 Low boiling node, in separating nonideal liquid mixtures, 22 303 Low-calorie beer, 3 577 Low calorie sweeteners, 12 38 Low calorific value (LCV) gas, 26 575—576... 

CORTIA (Ed.), Low-calorie Sweeteners Present and Future, Basle, Karger, 1999. mayer D g and kemper f h (Eds), Acesulfame K, New York, Marcel Dekker 1991. 

Curculin which is extracted with 0.5 M sodium chloride from the fruits of Curculigo latifolia and purified by ammonium sulphate fractionation, CM-sepharose ion-exchange chromatography and gel filtration.The protein acts as a low calorie sweetener and has a maximum sweetness equal to 0.35 M of sucrose. In addition to its sweetness, curculin also has taste modifying abilities since water and sour substances elicit a sweet taste after consumption of curculin. Currently, there is no other protein that has both sweet taste and taste modifying abilities. 

Rare or unnatural monosaccharides have many useful applications as nonnutritive sweeteners, glycosidase inhibitors and so on. For example, L-glucose and L-fructose are known to be low-calorie sweeteners. In addition, rare or unnatural monosaccharides are potentially useful as chiral building blocks for the synthesis of biologically active compounds. Therefore, these compounds have been important targets for the development of enzymatic synthesis based in the use of DHAP-dependent aldolases alone or in combination with isomerases. Fessner et al. showed that rare ketose-1-phosphates could be reached not only by aldol addition catalyzed by DHAP-dependent aldolases, but by enzymatic isomerization/ phosphorylation of aldoses [35]. Thus, for example, L-fructose can be prepared... 

Artificial sweeteners have also been developed to give the taste of sweetness without the calories. These chemicals have sweetness many times that of sugar so they sell for high prices as low-calorie sweeteners. Many artificial flavors have also been developed to replace natural biological flavors. In all cases we search for processes that convert inexpensive raw materials into chemicals that taste or smell like natural chemicals, either by producing the same chemical synthetically or by producing a different chemical that can replace the natural chemical. 

N and O function into the molecule and has been used to prepare hydroxyarginines (136,137), hydroxyornithines (136-138), p-lysine, p-leucine, and p-phenyl-p-alanine (139,140), the low-calorie sweetener aspartame (141) and the antitumor antibiotic acivicin (142-144). 

Nevertheless, one process for synthesis of the low calorie sweetener, Aspartame, which is a methyl ester of a dipeptide, (Asp-Phe-OMe) involves a biocatalytic step. Aspartic acid amino protected by benzyloxycarboi rl group, is reacted with two moles of phenylalanine methylester catalysed by the protease thermolysin. The extra mole of ester makes the dipeptide precipitate and it is later recycled. For details see section 4.6. 

As a consequence, in most cases, mixtures of low-calorie sweeteners are used to address this issue. At the same time, numerous sensory and consumer tests have shown major differences between low-calorie sweeteners and sucrose or HFCS with regard to body and aftertaste. 

Lactose has a sweetish taste, and is used extensively in the pharmaceutical industry. It is the second most widely used compound and is employed as a diluent, filler or binder in tablets, capsules and other oral product forms, a-lactose is used for the production of lactitol, which is present in diabetic products, low calorie sweeteners and slimming products. As lactose is only 30 per cent as sweet as sugar it is used as a sugar supplement, and also in food and confectionery. It is used in infant milk formulas. 

D. C. White, Proceedings of the American Chemical S ociety Low Calorie Sweetener and Carbohydrate Symposium, Los Angeles, Calif., 1988. 

Stevioside. Derived from the roots of the herb Stevio rebaudiana. this compound has found limited use in Japan and a few other countries as a low-calorie sweetener having about 300 times the sweetening power of sucrose. The compound has not been investigated thoroughly by a number of countries with strong regulatory agencies and, therefore, is not on the immediate horizon for wide consideration as a sweetener. 

In using low-calorie sweeteners in various food products, die problems are not limited to flavor, but often much more importantly involve texture, acidity, storage stability, and preservability. among others. Acceptable nonnutritively sweetened products cannot be developed by the simple substitution of artificial sweeteners for sugars. Rather, the new product must be completely reformulated from the beginning. Three examples follow. 

L Hough. High-intensity, low calorie sweeteners. In R Khan, ed. Low-Calorie Foods and Food Ingredients. New York Blackie Academic Professional, 1993, pp 138-164. 

This approach enables high peptide yields in equilibrium-controlled peptide synthesis in high-density aqueous media with an equimolar supply of substrates. Scale-up to molar amounts verified the concepts as well as demonstrate the synthetic utility of this approach Z-His-Phe-NH2 and Z-Asp-Phe-OMe, precursors for cyclo-[-His-Phe-] and the low-calorie sweetener Aspartame, respectively, were synthesized in preparative yields of 84-88% (Eichhom, 1997). For a review of the field of peptide synthesis in unusual media, see Jakubke (1996). 

Isomalt (5), also called Palatinit, is used as a low-calorie sweetener in some countries. It is a mixture of two compounds obtained by the hydrogenation of isomaltulose (6) (Scheme 4.4).15... 

Aspartame (a low calories sweetener) can also trigger urticaria (nettle rash), itchy hives, and swelling of the body (Bosso and Simon 2008). 

Fructans and fructose extracts, which can potentially be obtained from Jerusalem artichoke, have become attractive to industry for a number of food and nonfood applications because of their health benefits (e.g., Fleming and GrootWassink, 1979 Fontana et al., 1993 Fuchs, 1993 Roberfroid, 2005). Short-chain fructooligosaccharides (degree of polymerization of 2 to 5), for example, are increasingly used as low-calorie sweeteners in processed foods, and their utilization is anticipated to expand significantly in the future. 

Xylitol, another polyhydroxy compound, is used as a sweetener in sugarless gum. It has approximately the same number of calories per gram as does sucrose and is not a low-calorie sweetener. However, because it does not have a carbonyl group, it is not fermented by bacteria in the mouth and does not promote tooth decay. 

It has been suggested that sugars from the L series could be used as low-calorie sweeteners. These sugars cannot be metabolized in the normal way, as D sugars would, and therefore pass through the digestive system unaltered. Their effect on the body has not been sufficiently explored. 

A number of synthetic peptides are significant commercial products, ranging from the sweet dipeptide aspartame (L-aspartyl-L-phenylalanine methyl ester) to clinically used hormones such as insulin and oxytocin. L-Aspartyl-L-phenylalanine methyl ester (3 Scheme 2) is the methyl ester of the C-terminal dipeptide of gastrin. It was found accidently during the synthesis of gastrin that this synthetic sweetener is about 200 times as sweet as sucrose.f This pleasant sweetness without a bitter aftertaste was the reason that L-aspartyl-L-phenylalanine methyl ester was approved in many countries as a food additive, receiving much attention as a low-calorie sweetener. L-Aspartyl-L-phenylalanine methyl ester can be prepared by various chemical routes and the first enzymatic procedure of commercial interest was described by Isowa et al.h l In the industrial process,L-Asp and DL-Phe were chosen as inexpensive raw materials. L-Asp is available very inexpensively, whereas L-Phe is more expensive than DL-Phe. Z-D-Asp acts as a competitive inhibitor, while D-Phe-OMe... 

At the present time, the reported applications of the CR CSP have been limited to the separation of amino acids and some dipeptides as bulk substances. One example of the use of the CR CSP in a complex matrix was the direct stereochemical resolution of aspartame stereoisomers and their degradation products in coffee and diet soft drinks (76). Aspartame (N-DL-a-aspartyl-DL-phenylalanine methyl ester) is a dipeptide whose L,L-isomer is a low-calorie sweetener sold under the name NutraSweet. The structure of aspartame and its major degradation products are presented in Fig. 9 aiwl the stereochemical separation of these compounds on the CR CSP in Fig. lOA. The resolutions were accomplished using a mobile phase... 

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