Aspartame is an artificial, non-saccharide Sweetener used as a sugar substitute in some foods and beverages. In the European Union, it is codified as E951. Aspartame is a methyl ester of the aspartic acid/phenylalanine dipeptide. It was first sold under the brand name NutraSweet; It was first synthesized in 1965 and the patent expired in 1992.
The safety of aspartame has been the subject of several political and medical controversies, United States congressional hearings and Internet hoaxe, since its initial approval for use in food products by the U. S. Food and Drug Administration (FDA) in 1981. The European Food Safety Authority concluded in its 2013 re-evaluation that aspartame and its breakdown products are safe for human consumption at current levels of exposure, corroborating other medical reviews, However, because its breakdown products include phenylalanine, aspartame must be avoided by people with the genetic condition phenylketonuria (PKU).
Aspartame, an artificial sweetener, is approximately 200 times sweeter than sucrose. Due to this property, even though aspartame produces four kilocalories of energy per gram when metabolized, the quantity of aspartame needed to produce a sweet taste is so small that its caloric contribution is negligible.
The taste of aspartame and other artificial sweeteners differs from that of table sugar in the times of onset and how long the sweetness lasts, though aspartame comes closest to sugar's taste profile among approved artificial sweeteners.
The sweetness of aspartame lasts longer than sucrose, so it is often blended with other artificial sweeteners such as Acesulfame Potassium to produce an overall taste more like sugar. Aspartame can be synthesized from its constituent amino acids, L-phenylalanine and L-aspartate.