Acesulfame potassium
Acesulfame potassium ( ), also known as acesulfame K (K is the symbol for potassium) or Ace K, is a synthetic calorie-free sugar substitute (artificial sweetener) often marketed under the trade names Sunett and Sweet One. In the European Union, it is known under the E number (additive code) E950. It was discovered accidentally in 1967 by German chemist Karl Clauss at Hoechst AG (now Nutrinova). In chemical structure, acesulfame potassium is the potassium salt of 6-methyl-1,2,3-oxathiazine-4(3"H")-one 2,2-dioxide. It is a white crystalline powder with molecular formula and a molecular weight of 201.24 g/mol. Properties . Acesulfame K is 200 times sweeter than sucrose (common sugar), as sweet as aspartame, about two-thirds as sweet as saccharin, and one-third as sweet as sucralose. Like saccharin, it has a slightly bitter aftertaste, especially at high concentrations. Kraft Foods patented the use of sodium ferulate to mask acesulfame's aftertaste. Acesulfame K is often blended with other sweeteners (usually sucralose or aspartame). These blends are reputed to give a more sucrose-like taste whereby each sweetener masks the other's aftertaste, or exhibits a synergistic effect by which the blend is sweeter than its components. Acesulfame potassium  has a smaller particle size than sucrose, allowing for its mixtures with other sweeteners to be more uniform. Unlike aspartame, acesulfame K is stable under heat, even under moderately acidic or basic conditions, allowing it to be used as a food additive in baking, or in products that require a long shelf life. Although acesulfame potassium has a stable shelf life, it can eventually degrade to acetoacetamide, which is toxic in high doses. In carbonated drinks, it is almost always used in conjunction with another sweetener, such as aspartame or sucralose. It is also used as a sweetener in protein  shakes and pharmaceutical products, especially chewable and liquid medications, where it can make the active ingredients more palatable. The acceptable daily intake of acesulfame potassium is listed as 15 mg/kg/day. Acesulfame potassium is widely used in the human diet and excreted by the kidneys. It thus has been used by researchers as a marker to estimate to what degree swimming pools are contaminated by urine. Other names for acesulfame K are potassium acesulfamate, potassium salt of 6-methyl-1,2,3-oxothiazin-4(3"H")-one-2,3-dioxide, and potassium 6-methyl-1,2,3-oxathiazine-4(3"H")-one-3-ate-2,2-dioxide. Effect on body weight. Acesulfame potassium provides a sweet taste with  no caloric value. There is no high-quality evidence that using acesulfame potassium as a sweetener affects body weight or body mass index (BMI). Discovery. Acesulfame potassium was developed after the accidental discovery of a similar compound (5,6-dimethyl-1,2,3-oxathiazin-4(3H)-one 2,2-dioxide) in 1967 by Karl Clauss and Harald Jensen at Hoechst AG. After accidentally dipping his fingers into the chemicals with which he was working, Clauss licked them to pick up a piece of paper. Clauss is the inventor listed on a United States patent issued in 1975 to the assignee Hoechst Aktiengesellschaft for one process of manufacturing acesulfame  potassium. Subsequent research showed a number of compounds with the same basic ring structure had varying levels of sweetness. 6-methyl-1,2,3-oxathiazine-4(3"H")-one 2,2-dioxide had particularly favourable taste characteristics and was relatively easy to synthesize, so it was singled out for further research, and received its generic name (acesulfame-K) from the World Health Organization in 1978. Acesulfame potassium first received approval for table top use in the United States in 1988. Safety. As with other artificial sweeteners, concern exists over the safety of acesulfame potassium. However, the United States Food and Drug Administration (FDA) has approved its general use . Critics say acesulfame potassium has not been studied adequately and may be carcinogenic, although these claims have been dismissed by the European Food Safety Authority and FDA. Environment Canada tested the water from the Grand River at 23 sites between its headwaters and where it flows into Lake Erie. The results suggest that acesulfame appears in far higher concentrations than saccharin or sucralose at the various test sites. More recently the environmental fate and effects of acesulfame potassium have been reviewed by Belton et al. (2020).