Aspartame

The chemical name for aspartame is L-aspartyl-L-phenylalamine methyl ester. 

It is a white crystalline powder and is about 200 times as sweet as sucrose. It is noted for a clean, sweet taste that is similar to that of sucrose. 

Aspartame is the most widely used artificial sweetener in the world. It was approved by the FDA for use in the USA in 1981, and now is approved for use in several other countries of the world. One of the drawbacks of aspartame is its instability to heat and acid. Under acidic conditions aspartame slowly hydrolyzes leading to a loss of sweetness, chemical interaction, and microbial degradation. The shelf life of the aspartame-sweetened products with high water content is limited to about 6 months, after which it breaks down into its constituent components and loses its sweetening abilities. At elevated temperatures, solid aspartame slowly releases methanol to form aspartyl phenylalamine and the dioxopiperazine. This reaction is especially favored at neutral and alkaline pH values. Because of this reason, aspartame cannot be used in hot baking foods. 

There is no commonly accepted optimum blend maximum synergy occurs with a 50 50 blend, but use generally appears to have shifted from 50 50 blends to aspartame-rich blends in the range 30 70 to 10 90 acesulfame K aspartame. This may be to take advantage of improved stability of these blends (see Section 

3 Regulatory. Acesulfame K is widely permitted across the globe. 

Aspartame is the generic name for IV-ai-aspartyl-L-phenylalanine methyl ester. It is composed of two amino acids, L-aspartic acid and L-phenylalanine, joined by a methyl ester link. It was discovered in 1965 by J. Schlatter at the G.D. Searle Laboratories. It is a white crystalline product and its solubility in water is 10 g/1 at 20°C this figure increases at elevated temperatures and in acidic conditions (Ajinomoto Aspartame Technical Bulletin, 2003). It is sparingly soluble in other solvents. 

The taste profile of aspartame is similar to sucrose sweetness (Ripper et al., 1985). It is approximately 200 times as sweet as sucrose. It is synergistic with saccharin, cyclamate, stevioside, acesulfame K and many sugars, in particular fructose, but has little sweetness intensity synergy with sucralose. 

The maximum use level in soft drinks within the European Union is 600 rng/1, which means that, unlike most other intense sweeteners, it can be used as the sole sweetener in soft drinks. 

Chemical Name N-L-a-Aspartyl-L-phenylalanine 1-methyl ester Common Name — 

Trade Name Manufacturer Country Year Introduced 

N-Benzyloxycarbonyl-L-aspartic acid-a-p-nitrophenyl, /3-benzyl Diester Hydrogen 

A solution of 88.5 parts of L-phenylalanine methyl ester hydrochloride in 100 parts of water is neutralized by the addition of dilute aqueous potassium bicarbonate, then is extracted with approximately 900 parts of ethyl acetate. The resulting organic solution is washed with water and dried over anhydrous magnesium sulfate. To that solution is then added 200 parts of N-benzyloxycarbonyl-L-aspartic acid-a-p-nitrophenyl, -benzyl diester, and that reaction mixture is kept at room temperature for about 24 hours, then at approximately 65°C for about 24 hours. The reaction mixture is cooled to room temperature, diluted with approximately 390 parts of cyclohexane, then cooled to approximately -18°C in order to complete crystallization. The resulting crystalline product is isolated by filtration and dried to afford -benzyl N-benzyloxycarbonvI-L-aspartyl-L-phenylalanine methyl ester, melting at about 118.5°-119.5°C. 

To a solution of 180 parts of -benzyl N-benzyloxycarbonyl-L-aspartvI-L-phenylalanine methyl ester in 3,000 parts by volume of 75% acetic acid is added 18 parts of palladium black metal catalyst, and the resulting mixture is shaken with hydrogen at atmospheric pressure and room temperature for about 12 hours. The catalyst is removed by filtration, and the solvent is distilled under reduced pressure to afford a solid residue, which is purified by re-crystallization from aqueous ethanol to yield L-aspartyl-L-phenylalanine methyl ester. It displays a double melting point at about 190°C and 245°-247°C. 

3-Amino-N-(a-carboxyphenethyl)succinamic acid N-methyl ester 3-amino-N-(a-methoxycarbonylphenethyl)succinamic acid APM aspartyl phenylamine methyl ester Canderel E951 Equal, methyl N-a-L-aspartyl-L-phenylalaninate NutraSweet Pal Sweep, Pal Sweet Diet-, Sanecta SC-18862 Tri-Sweet. 

Aspartame is used as an intense sweetening agent in beverage products, food products, and table-top sweeteners, and in pharmaceutical preparations including tablets, powder mixes, and vitamin preparations. It enhances flavor systems and can be used to mask some unpleasant taste characteristics the approximate sweetening power is 180-200 times that of sucrose. 

Unlike some other intense sweeteners, aspartame is metabolized in the body and consequently has some nutritive value 1 g provides approximately 17kJ (4kcal). However, in practice, the small quantity of aspartame consumed provides a minimal nutritive effect. 

Therapeutically, aspartame has also been used in the treatment of sickle cell anemia.  

Aspartame occurs as an off white, almost odorless crystalline powder with an intensely sweet taste. 

The sweetness of acesulfame is perceived quickly and this substance is practically stable in foods under the common processing and storage conditions. It is used in a large number of different products. 

A dipeptide, L-aspartyl-L-phenylalanine methyl ester (L-Asp-L-Phe-OMe), has recently been 

The ADI values stipulated for aspartame and diketopiperazine are 0-40 mg/kg of body weight and 0-7.5 mg/kg of body weight. 

Aspartame synthesis on a large scale is achieved by the following reactions  

Amides of dipeptides consisting of L-aspartic acid and D-alanine are sweet (Table 8.11). The compound alitame is the N-3-(2,2,4,4-tetra-methyl)-thietanylamide of L-Asp-D-Ala (Formula 8.20) and with /sac,g(10) = 2000, it is a potential sweetener. 

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Aspartame is the market leader among artifi cial sweeteners It is a methyl ester of a dipeptide un related to any carbohydrate It was discovered in the course of research directed toward developing drugs to relieve indigestion... 

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 ... 

Foods sweetened with Aspartame (page 1051) con tain a PKU warning Can you see whyi... 

Procedures for determining the concentrations of caffeine, benzoic acid and aspartame in soda by these three methods are provided. In the example provided in this paper, the concentrations of caffeine and benzoic acid in Mello Yellow are determined spectrophotometrically. 

The concentrations of benzoic acid, aspartame, caffeine, and saccharin in a variety of beverages are determined in this experiment. A Gig column and a mobile phase of 80% v/v acetic acid (pH = 4.2) and 20% v/v methanol are used to effect the separation. A UV detector set to 254 nm is used to measure the eluent s absorbance. The ability to adjust retention times by changing the mobile phase s pH is also explored. 

Caffeine, benzoic acid, and aspartame in soft drinks are analyzed by three methods. Using several methods to analyze the same sample provides students with the opportunity to compare results with respect to accuracy, volume of sample required, ease of performance, sample throughput, and detection limit. 

Suppose that you are to separate a mixture of benzoic acid, aspartame, and caffeine in a diet soda. The following information is available to you. 

Diet soft drinks contain appreciable quantities of aspartame, benzoic acid, and caffeine. What is the expected order of elution for these compounds in a capillary zone electrophoresis separation using a pH 9.4 buffer solution, given that aspartame has pJC values of 2.964 and 7.37, benzoic acid s pfQ is 4.2, and the pfQ for caffeine is less than 0. 

There are thousands of breweries worldwide. However, the number of companies using fermentation to produce therapeutic substances and/or fine chemicals number well over 150, and those that grow microorganisms for food and feed number nearly 100. Lists of representative fermentation products produced commercially and the corresponding companies are available (1). Numerous other companies practice fermentation in some small capacity because it is often the only route to synthesize biochemical intermediates, enzymes, and many fine chemicals used in minor quantities. The large volume of L-phenylalanine is mainly used in the manufacture of the artificial dipeptide sweetener known as aspartame [22389-47-0]. Prior to the early 1980s there was httle demand for L-phenyl alanine, most of which was obtained by extraction from human hair and other nonmicrobiological sources. 

USP grade. Estimated production cost. Majority is used to make aspartame. ... 

Formic acid is used as an intermediate in the production of a number of dmgs, dyes, flavors, and perfume components. It is used, for example, in the synthesis of aspartame and in the manufacture of formate esters for flavor and fragrance appHcations. 

Fumaric acid and malic acid [6915-15-7] are produced from maleic anhydride. The primary use for fumaric acid is in the manufacture of paper siting products (see Papermaking additives). Fumaric acid is also used to acidify food as is malic acid. Malic acid is a particularly desirable acidulant in certain beverage selections, specifically those sweetened with the artificial sweetener aspartame [22839-47-0]. 

There are numerous further appHcations for which maleic anhydride serves as a raw material. These appHcations prove the versatiHty of this molecule. The popular artificial sweetener aspartame [22839-47-0] is a dipeptide with one amino acid (l-aspartic acid [56-84-8]) which is produced from maleic anhydride as the starting material. Processes have been reported for production of poly(aspartic acid) [26063-13-8] (184—186) with appHcations for this biodegradable polymer aimed at detergent builders, water treatment, and poly(acryHc acid) [9003-01-4] replacement (184,187,188) (see Detergency). 

An estimation of the amount of amino acid production and the production methods are shown ia Table 11. About 340,000 t/yr of L-glutamic acid, principally as its monosodium salt, are manufactured ia the world, about 85% ia the Asian area. The demand for DL-methionine and L-lysiae as feed supplements varies considerably depending on such factors as the soybean harvest ia the United States and the anchovy catch ia Pern. Because of the actions of D-amiao acid oxidase and i.-amino acid transamiaase ia the animal body (156), the D-form of methionine is as equally nutritive as the L-form, so that DL-methionine which is iaexpensively produced by chemical synthesis is primarily used as a feed supplement. In the United States the methionine hydroxy analogue is partially used ia place of methionine. The consumption of L-lysiae has iacreased ia recent years. The world consumption tripled from 35,000 t ia 1982 to 100,000 t ia 1987 (214). Current world consumption of L-tryptophan and i.-threonine are several tens to hundreds of tons. The demand for L-phenylalanine as the raw material for the synthesis of aspartame has been increasing markedly. 

Aspartame (L-aspartyl-L-phenylalanine methyl ester [22839-47-0]) is about 200 times sweeter than sucrose. The Acceptable Daily Intake (ADI) has been estabUshed by JECFA as 40 mg/kg/day. Stmcture-taste relationship of peptides has been reviewed (223). Demand for L-phenylalanine and L-aspartic acid as the raw materials for the synthesis of aspartame has been increasing, d-Alanine is one component of a sweetener "Ahtame" (224). 

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). 

Sucrose occupies a unique position in the sweetener market (Table 3). The total market share of sucrose as a sweetener is 85%, compared to other sweeteners such as high fmctose com symp (HFCS) at 7%, alditols at 4%, and synthetic sweeteners (aspartame, acesulfame-K, saccharin, and cyclamate) at 4%. The world consumption of sugar has kept pace with the production. The rapid rise in the synthetic sweetener market during 1975—1995 appears to have reached a maximum. 

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). 

Eig. 1. Stabihty of aspartame in water at 25°, where is the half-life (21). 

The principal pathway for the decomposition of aspartame begins with the cleavage of the ester bond, which may or may not be accompanied by cyclization (Eig. 2). The resultant diketopipera2ine and/or dipeptide can be further hydroly2ed into individual amino acids (qv). 

Fig. 2. Decomposition of aspartame to diketopipera2ine and/or aspartyl-phenylalanine and then to the amino acids aspartic acid and phenylalanine (22).

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