Nutrition aspartame

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. 

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. 

Some sources consider aspartame a nutritive sweetener. It is sensitive to low pH and high temperatures and degrades over time. Aspartame can be used alone or in a blend with other sweeteners. 

Saccharin is a non-nutritive sweetener used in toothpastes, cold remedies, ice creams, and coffee-sweetening packets. Its use in soft drinks has been almost entirely replaced by aspartame. 

Every patient with diabetes requires some form of dietary assessment, and often therapy. This is important to allocate the relative amounts of energy derived from carbohydrate, protein and fat of total recommended daily calories in proportion to the patient s body weight and height and daily requirements, while avoiding atherogenic diets. Diets with high carbohydrate content (50-60%), low fat (30-35%) and adequate protein (10-15%) is recommended. Fibre-rich foods are preferable. The use of non-nutritive sweeteners (saccharin, aspartame, ace-sulfame K and sucralose) are acceptable. Alcohol intake should be assessed since excess consumption... 

Aspartame. This synthetic sweetener is included with the nutritive sweeteners because it does have some caloric value (when metabolized as a protein, it releases 4 keal/g). The relationship between sweetness of aspartame and sucrose is almost linear when plotted on a log-log scale. Aspartame is 182 times sweeter than a 2% sucrose solution, but only 43 times sweeter than a 30% solution. The clean, full sweetness of aspartame is similar to that of sucrose and complements other flavors. 

Paradoxically, the nutritional component of greatest commercial significance is the absence of nutrition, achieved by substituting carbohydrate sweeteners with non-nutritive sweeteners such as saccharin and acesulfame-K, or the amino acid sweetener aspartame. 

Nutritional ingredients (e.g., relatively small molecules, such as carotenoids, (pro)vitamins, anti-oxidants, preservatives, polyunsaturated fatty acids, aspartame, and tailored peptide mixes). 

Sweeteners can be divided into two groups, nonnutritive and nutritive sweeteners. The nonnutritive sweeteners include saccharin, cyclamate, aspartame, acesulfame K, and sucralose. There are also others, mainly plant extracts, which are of limited importance. The nutritive sweeteners are sucrose glucose fructose invert sugar and a variety of polyols including sorbitol, mannitol, malt-itol, lactitol, xylitol, and hydrogenated glucose syrups. 

To illustrate a few aspects of amino add production by enzymatic methods, ffie production of L-phenylalanine will be considered in some detail. L-Phenylalanine is important as an essential amino add for human nutrition and is used as an intermediate for the synthesis of the artifidal sweetener, aspartame. Other examples of the industrial production of amino adds by enzymatic methods are described briefly in Appendix 2. 

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. 

Stegink LD, Filer LJ Jr., and Baker GL (1979) Plasma erythrocyte and human milk levels of free amino acids in lactating women administered aspartame or lactose. Journal of Nutrition 109 2173-2181. 

Use (l isomer) Medicine and nutrition, essential ingredients of Aspartame. Available commercially as DL-dihydroxyphenylalanine and as DL-phenylala-nine. 

New uses have also been discovered, from the synthesis of high purity synthetic diamonds to the production of the nutritive sweetener aspartame it was also used as fuel in molecular motors. The book Phosgenations - A Handbook [55] discusses in detail novel and old uses of phosgene (see Sections 1.4 and 1.5, in particular). 

Isolation of the amino acids from such wastewaters might be of commercial value. For example, L-phenylalanine has been used as a precursor in the synthesis of a variety of industrial products, for example, the artificial sweetener Aspartame [117]. Purified amino acids can, on the other hand, be used as nutritional supplements in the diet of livestock [118], as weU as in human nutrition [119]. Therefore, there is potential for the extraction of amino acids from dairy and proteinaceous wastewaters for additional income of the producing industries. Application of LMs in treatment of such wastewaters could be of substantial benefit. 

Enantiomerically pure a-H-amino acids are intermediates in the synthesis of antibiotics used for parenteral nutrition and for food and feed additives (see also Chapter 12.2). Examples are D-phenylglycine and 4-hydroxyphenylalanine for semisynthetic (3-lactam antibiotics and L-phenylalanine for the peptidic sweetener aspartame. DSM used this process to produce also L-homophenylalanine, a potential precursor molecule for several ACE-inhibitors. 

L-Aspartate is used in parenteral nutrition and food additives, and as a starting material for the low-calorie sweetener aspartame, aspartyl-phenylalanine methyl ester. Recently, the possibility of using L-aspartate as a raw material for polymer production was studied very hard since it has three reactive residues in the molecule and the resulted polymers could be biodegradative. It is used as a detergent and chelating or water treating agent. 

In human nutrition, free amino acids play an important role in aromatisa-tion, as flavour enhancers, and as sweeteners. Monosodium glutamate, in concentrations of 0.1-0.4%, is probably the most prominent flavour enhancer for spices, soups, sauces, meat and fish. (L)-Cysteine amplifies the flavour of onions. Glycine is used to mask the aftertaste of saccharin. Whereas (L)-amino acids may taste slightly bitter, the (D)-enantiomers have a sweet taste. This is in general also true for the corresponding di- and oligopeptides - except for the methyl ester of (L)-aspartyl-(L)-phenylalanine (Aspartame). 

Thaumatin is a group of intensely sweet basic proteins isolated from the fruit of Thaumatococcus danielli (West African Katemfe fruit). It consists essentially of the proteins Thaumatin I and Thaumatin II. Thaumatin is a taste-modifying protein that functions as natural sweetener or flavor enhancer. Thaumatin is stable in aqueous solutions between pH 2.0 and 10 at room temperature. As occurs with aspartame it is nutritive, containing 4kcalg , but due to its intense sweetness, the amounts used are small enough for thaumatin to be considered and classified as a nonnutritive sweetener. Thaumatin is approved for a number of uses in UK, Japan, Australia, the EU, and in many other countries. In the USA, it is approved as a flavor enhancer. 

Phenylalanine is the precursor of the artificial sweetener aspartame and used in feed and infusion solutions, nutrition, and health. The increasing demand ftrr the low calorie artificial sweetener has been driving the phenylalanine production.Tyrosine has its potential use in the manufacture of DOPA (dihydroxyphenylalanine) for the treatment of Parkinson s disease. 

Aspartame is a nutritive sweetener approximately 200 times as sweet as sucrose, which was discovered in 1969. Its chemical constitution is a-L-aspartyl-L-phenyl-alanine methyl ester 1165, which can be advantageously and regioselectively produced from L-Asp(OMe)-NCA 1162f and H-Phe-OMe 1163f. This protocol is shorter by several preparative and separatory steps compared with other syntheses [834]. 

Schirle-KeUer, J.-R, Flavor Interactions with Fat Replacers and Aspartame, Ph.D. thesis Food Science and Nutrition, University of Minnesota, St. Paul, p. 237, 1995. 

Sweeteners are natural or synthetic compounds which imprint a sweet sensation and possess no or negligible nutritional value ( nonnutritive sweeteners ) in relation to the extent of sweetness. There is considerable interest in new sweeteners. The rise in obesity in industrialized countries has established a trend for calorie-reduced nutrition. Also, there is an increased discussion about the safety of saccharin and cyclamate, the two sweeteners which were predominant for a long time. The search for new sweeteners is complicated by the fact that the relationship between chemical structure and sweetness perception is not yet satisfactorily resolved. In addition, the safety of suitable compounds has to be certain. Some other criteria must also be met, for example, the compound must be adequately soluble and stable over a wide pH and temperature range, have a clean sweet taste without side or post-flavor effects, and provide a sweetening effect as cost-effectively as does sucrose. At present, some new sweeteners are on the market (e. g., acesulfame and aspartame). The application of a number of other compounds will be discussed here. 

Sweet peptides (such as aspartame), proteins (e.g. thaumatin) and glycosides (stevioside), are a source of some energy, but in the quantities in which they are used, their contribution to the total energy intake is insignificant. These sweeteners are therefore ranked among non-nutritional sweeteners in Section 11.3.2.1.2. 

The determination of the concentration of sweeteners in food items and beverages is of great importance for the safe and sustainable consumption of dietetic products. In particular, the assessment of the levels of aspartame is almost mandatory because of toxicity and accumulation issues. The analysis of series of samples using automated high-throughput methods would be very useful for the elaboration of databases of aspartame content that could constitute important tools for health professionals and consumers. The implementation of automated methods in the food industries could permit easy postproduction evaluation of sweetener contents to provide information that can contribute to nutritional tables. 

The amino acids in nutritional matrices may be present as free amino acids, peptides, proteins, and/or in polymers with nonpeptide bonds. Each of these forms may need to be prepared for analysis by different methods. Free amino acids can be directly extracted from the matrix and analyzed. Peptides and proteins must be hydrolyzed to free the amino acids before analysis. The analyses of the hydrolyzed matrices will give total amino acids, that is, those amino acids that were part of peptides/proteins as well as any free amino acids. The analysis of nonpeptide bonded polymers of amino acids such as aspartame often needs to be analyzed by specialized methods. 

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