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Aspartame[1]
Aspartame
Ball-and-stick model of aspartame
Names
IUPAC names
N-(L-α-Aspartyl)-L-phenylalanine,
1-methyl ester
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.041.132 Edit this at Wikidata
E number E951 (glazing agents, ...)
  • InChI=1/C14H18N2O5/c1-21-14(20)11(7-9-5-3-2-4-6-9)16-13(19)10(15)8-12(17)18/h2-6,10-11H,7-8,15H2,1H3,(H,16,19)(H,17,18)/t10-,11-/m0/s1
    Key: IAOZJIPTCAWIRG-QWRGUYRKBV
  • O=C(O)C[C@H](N)C(=O)N[C@H](C(=O)OC)Cc1ccccc1
Properties
C14H18N2O5
Molar mass 294.307 g·mol−1
Density 1.347 g/cm3
Melting point 246–247 °C
Boiling point decomposes
sparingly soluble
Solubility slightly soluble in ethanol
Acidity (pKa) 4.5-6.0 [2]
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Aspartame (or APM) (Template:PronEng or /əˈspɑrteɪm/) is the name for an artificial, non-saccharide sweetener used as a sugar substitute in many foods and beverages. In the European Union, it is known under the E number (additive code) E951. Aspartame is the methyl ester of a phenylalanine/aspartic acid dipeptide.

Aspartame was first synthesized in 1965. Its use in food products was first approved by the United States Food and Drug Administration in 1974. Because its breakdown products include phenylalanine, aspartame is among the many substances that must be avoided by people with the genetic condition phenylketonuria (PKU).

A recent medical review on the subject concluded that "the weight of existing scientific evidence indicates that aspartame is safe at current levels of consumption as a non-nutritive sweetener".[3]

The safety of aspartame has been the subject of several political and medical controversies, Congressional Hearings and internet hoaxes since its initial approval by the U.S. Food and Drug Administration (FDA) in 1974.

Chemistry

Aspartame is the methyl ester of the dipeptide of the natural amino acids L-aspartic acid and L-phenylalanine. Under strongly acidic or alkaline conditions, aspartame may generate methanol by hydrolysis. Under more severe conditions, the peptide bonds are also hydrolyzed, resulting in the free amino acids.[4]

For some markets, aspartame is manufactured from phenylalanine produced by a genetically modified strain of E. coli,[5][6] a bacterium used commonly in laboratory research and biotechnology.[7]

Properties and use

Aspartame is an artificial sweetener. It is 200 times sweeter than sugar in typical concentrations, without the high energy value of sugar.[8] While aspartame, like other peptides, has a caloric value of 4 kilocalories (17 kilojoules) per gram, the quantity of aspartame needed to produce a sweet taste is so small that its caloric contribution is negligible. The taste of aspartame is not identical to that of sugar: the sweetness of aspartame has a slower onset and longer duration than that of sugar. Blends of aspartame with acesulfame potassium—usually listed in ingredients as acesulfame K— are said to taste more like sugar,[9] and to be sweeter than either substitute used alone.

Like many other peptides, aspartame may hydrolyze (break down) into its constituent amino acids under conditions of elevated temperature or high pH. This makes aspartame undesirable as a baking sweetener, and prone to degradation in products hosting a high-pH, as required for a long shelf life. The stability of aspartame under heating can be improved to some extent by encasing it in fats or in maltodextrin. The stability when dissolved in water depends markedly on pH. At room temperature, it is most stable at pH 4.3, where its half-life is nearly 300 days. At pH 7, however, its half-life is only a few days. Most soft-drinks have a pH between 3 and 5, where aspartame is reasonably stable. In products that may require a longer shelf life, such as syrups for fountain beverages, aspartame is sometimes blended with a more stable sweetener, such as saccharin.[10]

Aspartame's major decomposition products are diketopiperazine, aspartyl-phenylalanine, and phenylalanine,[11] as well as methanol.[12] At 180° C, aspartame undergoes decomposition to form a diketopiperazine (DKP) derivative.[13]

In products such as powdered beverages, the amine in aspartame can undergo a Maillard reaction with the aldehyde groups present in certain aroma compounds. The ensuing loss of both flavor and sweetness can be prevented by protecting the aldehyde as an acetal.

Some claim that aspartame leaves an odd after-taste, while others describe it as a non-flavor or watery after-taste.[14]

Discovery and approval

Aspartame was discovered in 1965 by James M. Schlatter, a chemist working for G.D. Searle & Company. Schlatter had synthesized aspartame in the course of producing an antiulcer drug candidate. He accidentally discovered its sweet taste when he licked his finger, which had become contaminated with aspartame.[15]

In 1980, the FDA convened a Public Board of Inquiry (PBOI) consisting of independent advisors charged with examining the purported relationship between aspartame and brain cancer. The PBOI concluded that aspartame does not cause brain damage, but it recommended against approving aspartame at that time, citing unanswered questions about cancer in laboratory rats. A U.S. FDA task force team investigated allegations of errors in the preapproval research conducted by the manufacturer, and found only minor discrepancies that did not affect the study outcomes.[16][17]

Citing data from a Japanese study that had not been available to the members of the PBOI,[18] and after seeking advice from an expert panel that found fault with statistical analyses underlying the PBOI's hesitation,[19] FDA commissioner Hayes approved aspartame for use in dry goods.[20] In 1983, the FDA further approved aspartame for use in carbonated beverages, and for use in other beverages, baked goods, and confections in 1993. In 1996, the FDA removed all restrictions from aspartame, allowing it to be used in all foods.

In 1984, Monsanto Company bought G.D. Searle—and the aspartame business became a separate Monsanto subsidiary, the NutraSweet Company. On May 25, 2000, Monsanto sold it to J.W. Childs Equity Partners II L.P.[21] The U.S. patent on aspartame expired in 1992. Since then, the company has competed for market share with other manufacturers, including Ajinomoto, Merisant and the Holland Sweetener Company. The latter stopped making the chemical in late 2006 because "global aspartame markets are facing structural oversupply, which has caused worldwide strong price erosion over the last five years", making the business "persistently unprofitable".[22]

Several European Union countries approved aspartame in the 1980s, with EU-wide approval in 1994. The European Commission Scientific Committee on Food reviewed subsequent safety studies and reaffirmed the approval in 2002. The European Food Safety Authority reported in 2006 that the previously established Acceptable Daily Intake was appropriate, after reviewing yet another set of studies.[23]

Metabolism and phenylketonuria

Upon ingestion, aspartame breaks down into natural residual components, including aspartic acid, phenylalanine, methanol,[24] and further breakdown products including formaldehyde[25] and formic acid, accumulation of the latter being suspected as the major cause of injury in methanol poisoning. Human studies show that formic acid is excreted faster than it is formed after ingestion of aspartate. In some fruit juices, higher concentrations of methanol can be found than the amount produced from aspartame in beverages.[26]

High levels of the naturally-occurring essential amino acid phenylalanine are a health hazard to those born with phenylketonuria (PKU), a rare inherited disease that prevents phenylalanine from being properly metabolized. Since individuals with PKU must consider aspartame as an additional source of phenylalanine, foods containing aspartame sold in the United States must state "Phenylketonurics: Contains Phenylalanine" on their product labels.[citation needed]

In the UK, foods that contain aspartame are legally required by the country's Food Standards Agency to list the chemical among the product's ingredients and carry the warning "Contains a source of phenylalanine" – this is usually at the foot of the list of ingredients. Manufacturers are also required to print '"with sweetener(s)" on the label close to the main product name' on foods that contain "sweeteners such as aspartame" or "with sugar and sweetener(s)" on "foods that contain both sugar and sweetener".[27]

Marketing

Equal, NutraSweet, and Canderel are ingredients of approximately 6,000 consumer foods and beverages sold worldwide, including (but not limited to) diet sodas and other soft drinks, instant breakfasts, breath mints, cereals, sugar-free chewing gum, cocoa mixes, frozen desserts, gelatin desserts, juices, laxatives, chewable vitamins supplements, milk drinks, pharmaceutical drugs and supplements, shake mixes, tabletop sweeteners, teas, instant coffees, topping mixes, wine coolers and yogurt. It is provided as a table condiment in some countries. Aspartame is less suitable for baking than other sweeteners, because it breaks down when heated and loses much of its sweetness. Aspartame is also one of the main sugar substitutes used by people with diabetes.

Ajinomoto

In 2004 the market for aspartame, in which the company Ajinomoto, the world's largest aspartame manufacturer, had a 40 percent share, was 14,000 metric tons a year, and consumption of the product was rising by 2 percent a year.[28] Ajinomoto acquired its aspartame business in 2000 from Monsanto for $67M.[29]

In 2008, Ajinomoto sued British supermarket chain Asda, part of Wal-Mart, for a malicious falsehood action concerning its aspartame product when the chemical was listed as excluded from the chains product line, along with other "nasties".[30] In July 2009, a British court found in favour of Asda.[31] In June 2010, an appeal court reversed the decision, allowing Ajinomoto to pursue a case against Asda to protect aspartame's reputation.[32] Asda said that it would continue to use the term "no nasties" on its own-label products.[33]

In November 2009, Ajinomoto announced a new brand name for its aspartame sweetener — AminoSweet.[34][35]

Competition

Because sucralose, unlike aspartame, retains its sweetness after being heated, and has at least twice the shelf life of aspartame, it has become more popular as an ingredient.[36] This, along with differences in marketing and changing consumer preferences, caused aspartame to lose market share to sucralose.[37][38] In 2004, aspartame traded at about $30/kg and sucralose, which is roughly three times sweeter by weight, at around $300/kg.[39].

Safety controversy

Main article: Aspartame controversy

"The FDA's own toxicologist, Dr. Adrian Gross told Congress that without a shadow of a doubt, aspartame can cause brain tumors and brain cancer and violated the Delaney Amendment which forbids putting anything in food that is known to cause Cancer. Detailed information on this can be found in the Bressler Report (FDA report on Searle)."

The artificial sweetener aspartame has been the subject of several controversies and hoaxes since its initial approval by the U.S. Food and Drug Administration (FDA) in 1974. Critics allege that conflicts of interest marred the FDA's approval of aspartame, question the quality of the initial research supporting its safety,[40][41][42] and postulate that numerous health risks may be associated with aspartame.

The validity of these claims has been examined and dismissed.[43][44][45] In 1987, the U.S. Government Accountability Office concluded that the food additive approval process had been followed properly for aspartame.[40][46] Aspartame has been found to be safe for human consumption by more than ninety countries worldwide,[47][48] with FDA officials describing aspartame as "one of the most thoroughly tested and studied food additives the agency has ever approved" and its safety as "clear cut".[49] The weight of existing scientific evidence indicates that aspartame is safe at current levels of consumption as a non-nutritive sweetener.[3]

Compendial status

References

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  1. ^ Merck Index, 11th Edition, 861.
  2. ^ Rowe, Raymond C. (2009). "Aspartame". Handbook of Pharmaceutical Excipients. pp. 11–12. ISBN 1582120587.
  3. ^ a b Magnuson BA, Burdock GA, Doull J; et al. (2007). "Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies". Critical Reviews in Toxicology. 37 (8): 629–727. doi:10.1080/10408440701516184. PMID 17828671. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link) Cite error: The named reference "CritReview" was defined multiple times with different content (see the help page).
  4. ^ David J. Ager, David P. Pantaleone, Scott A. Henderson, Alan R. Katritzky, Indra Prakash, D. Eric Walters (1998). "Commercial, Synthetic Non-nutritive Sweeteners". Angewandte Chemie International Edition. 37 (13–24): 1802–1817. doi:10.1002/(SICI)1521-3773(19980803)37:13/14<1802::AID-ANIE1802>3.0.CO;2-9.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ^ Woolf, Marie (June 20, 1999). "World's top sweetener is made with GM bacteria". The Independent. Retrieved June 28, 2010.
  6. ^ Method for production of L-phenylalanine by recombinant E. coli ATCC 67460
  7. ^ Sang Yup Lee, ed. (2009). "Preface". Systems Biology and Biotechnology of Escherichia coli. New York: Springer-Verlag. p. ix. ISBN 9781402093937. Retrieved June 28, 2010. For many decades, E. coli has been the organism of choice in studying basic microbiology, genetics and molecular biology as well as in developing important biotechnological applications. {{cite book}}: Unknown parameter |month= ignored (help)
  8. ^ "The Safety of Aspartame - New York Times". www.nytimes.com. Retrieved 2010-06-19.
  9. ^ "New Products Weigh In". www.foodproductdesign.com. Retrieved 2010-06-19.
  10. ^ "Fountain Beverages in the US" (PDF). The Coca-Cola Company. 2007. {{cite web}}: Unknown parameter |month= ignored (help)
  11. ^ Prodolliet, J.; Bruelhart, M. (1993). "Determination of aspartame and its major decomposition products in foods". J AOAC Int. 76 (2): 275–82. PMID 8471853. {{cite journal}}: Cite has empty unknown parameter: |month= (help)
  12. ^ Lin, SY.; Cheng, YD. (2000). "Simultaneous formation and detection of the reaction product of solid-state aspartame sweetener by FT-IR/DSC microscopic system". Food Addit Contam. 17 (10): 821–7. doi:10.1080/026520300420385. PMID 11103265. {{cite journal}}: Unknown parameter |month= ignored (help)
  13. ^ Rastogi, S.; Zakrzewski, M.; Suryanarayanan, R. (2001). "Investigation of solid-state reactions using variable temperature X-ray powder diffractrometry. I. Aspartame hemihydrate". Pharm Res. 18 (3): 267–73. doi:10.1023/A:1011086409967. PMID 11442263. {{cite journal}}: Unknown parameter |month= ignored (help)
  14. ^ "Has aspartame an aftertaste". Institute of Food Technologists. 1985. {{cite web}}: Unknown parameter |month= ignored (help)
  15. ^ Magnuson BA, Burdock GA, Doull J (2007). "Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies". Crit. Rev. Toxicol. 37 (8): 629–727. doi:10.1080/10408440701516184. PMID 17828671.{{cite journal}}: CS1 maint: multiple names: authors list (link) Citing: Mazur, R.H. (1984). Discovery of aspartame. In Aspartame: Physiology and Biochemistry (L. D. Stegink and L. J. Filer Jr., Eds.). Marcel Dekker, New York, pp. 3–9.
  16. ^ "U.S. GAO - HRD-87-46 Food and Drug Administration: Food Additive Approval Process Followed for Aspartame, June 18, 1987". pp. 94–96. Retrieved 2008-09-05.
  17. ^ Testimony of Dr. Adrian Gross, Former FDA Investigator to the U.S. Senate Committee on Labor and Human Resources, November 3, 1987. Hearing title: "NutraSweet Health and Safety Concerns." Document # Y 4.L 11/4:S.HR6.100, page 430-439.
  18. ^ FDA Statement on Aspartame, November 18, 1996
  19. ^ "U.S. GAO - HRD-87-46 Food and Drug Administration: Food Additive Approval Process Followed for Aspartame, June 18, 1987". p. 53. Retrieved 2008-09-05.
  20. ^ Food Additive Approval Process Followed for Aspartame, Food and Drug Administration, June 1987
  21. ^ J.W. Childs Equity Partners II, L.P, Food & Drink Weekly, June 5, 2000
  22. ^ html b1?release id=115447
  23. ^ EFSA ::. Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC) related to a new long-term carcinogenicity study on aspartame
  24. ^ Roberts HJ (2004). "Aspartame disease: a possible cause for concomitant Graves' disease and pulmonary hypertension". Texas Heart Institute Journal. 31 (1): 105, author reply 105–6. PMC 387446. PMID 15061638.
  25. ^ Trocho C, Pardo R, Rafecas I; et al. (1998). "Formaldehyde derived from dietary aspartame binds to tissue components in vivo". Life Sciences. 63 (5): 337–49. doi:10.1016/S0024-3205(98)00282-3. PMID 9714421. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  26. ^ Stegink, Lewis D. (1987). "The aspartame story: a model for the clinical testing of a food additive". American Journal of Clinical Nutrition. 46 (1): 204–215. PMID 3300262. {{cite journal}}: Unknown parameter |month= ignored (help)
  27. ^ Aspartame - Labelling, UK Food Standards Agency, 18 July 2006. Retrieved on 2007-07-22.
  28. ^ "Ajinomoto May Exceed Full-Year Forecasts on Amino Acid Products - Bloomberg". www.bloomberg.com. Retrieved 2010-06-23.
  29. ^ "Sweetener sale-05/06/2000-ECN". www.icis.com. Retrieved 2010-07-09.
  30. ^ "Asda gears up for additives battle/ aspartame". www.thisismoney.co.uk. Retrieved 2010-06-23. {{cite web}}: Text "This is Money" ignored (help)
  31. ^ "Asda claims victory in aspartame 'nasty' case". www.foodanddrinkeurope.com. Retrieved 2010-06-23.
  32. ^ "FoodBev.com". www.foodbev.com. Retrieved 2010-06-23. {{cite web}}: Text "Court of Appeal rules in Ajinomoto/Asda aspartame case" ignored (help)
  33. ^ "Radical new twist in Ajinomoto vs Asda 'nasty' battle". www.foodnavigator.com. Retrieved 2010-06-23.
  34. ^ "Ajinomoto brands aspartame AminoSweet". Foodnavigator.com. Retrieved 2010-07-07.
  35. ^ "Ajinomoto brands aspartame 'AminoSweet'". FoodBev.com. 2009-11-17. Retrieved 2010-07-07.
  36. ^ "A Something Among the Sweet Nothings; Splenda Is Leaving Other Sugar Substitutes With That Empty Feeling - New York Times". query.nytimes.com. Retrieved 2010-06-18.
  37. ^ John Schmeltzer (2004-12-02). "Equal fights to get even as Splenda looks sweet]" (subscription required). Chicago Tribune. Retrieved 2007-07-04.
  38. ^ Carney, By Beth (2005-01-19). "It's Not All Sweetness for Splenda". BusinessWeek: Daily Briefing. Retrieved 2008-09-05.
  39. ^ "Aspartame defence courts reaction". www.beveragedaily.com. Retrieved 2010-07-07.
  40. ^ a b GAO 1987. "Food Additive Approval Process Followed for Aspartame" Full GAO Report United States General Accounting Office, GAO/HRD-87-46, June 18, 1987
  41. ^ Sugarman, Carole (1983-07-03). "Controversy Surrounds Sweetener". Washington Post. pp. D1–2. Retrieved 2008-11-25. {{cite news}}: Italic or bold markup not allowed in: |publisher= (help)
  42. ^ Henkel J (1999). "Sugar substitutes. Americans opt for sweetness and lite". FDA Consumer Magazine. 33 (6). DIANE Publishing: 12–6. ISBN 9781422326909. PMID 10628311.
  43. ^ the University of Hawaii. "Falsifications and Facts about Aspartame - An analysis of the origins of aspartame disinformation" (PDF).
  44. ^ "Aspartame Warning". About.com. - the Nancy Markle chain email.
  45. ^ Deconstructing Web Pages - An exercise deconstructing a web page to determine its credibility as a source of information, using the aspartame controversy as the example.
  46. ^ GAO 1986. "Six Former HHS Employees' Involvement in Aspartame's Approval." United States General Accounting Office, GAO/HRD-86-109BR, July 1986.
  47. ^ Health Canada: "Aspartame - Artificial Sweeteners". Retrieved 2008-11-08.
  48. ^ Food Standards Australia New Zealand: "Food Standards Australia New Zealand: Aspartame (September 2007)". Retrieved 2008-11-08.
  49. ^ Henkel, John (November–December 1999). "Sugar Substitutes: Americans Opt for Sweetness and Lite". FDA Consumer. Retrieved January 29, 2009. {{cite news}}: Check date values in: |date= (help)
  50. ^ British Pharmacopoeia Commission Secretariat. "Index (BP)" (PDF). Retrieved 16 January 2010. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
  51. ^ United States Pharmacopeia. "Food Ingredient Reference Standards" (PDF). Retrieved 16 January 2010. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
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