Chemistry
Saccharin is a sulfimide. The hydrogen atom on the nitrogen atom is quite acidic (pKa ~2) and it readily forms salts as shown below. The sweetener is usually sold as the sodium salt. This page uses the Jmol java applet. Be sure your browser is java-enabled. Be patient--it may take several seconds for the structure to load!
Data for sodium saccharin: Molecular formula: C7H4NNaO3S Molecular weight: 205.16 Solubility: 1 g in 1.2 mL water (sodium salt).
Discovery
There is some controversy over the discovery of saccharin. Constantine Fahlberg was working in the laboratory of Ira Remsen at Johns Hopkins University. According to Fahlberg's account, he accidentally spilled some laboratory material on his hand, and noticed the sweet taste later in the evening when he was eating dinner. Fahlberg and Remsen published the work jointly (Fahlberg, C.; Remsen, I. Ueber die Oxydation des Orthotoluolsulfamids. Chem. Ber. 1879, 12, 469-473.). Later Fahlberg patented saccharin without including Remsen on the patent. Fahlberg went on to become wealthy. Remsen went on to become the president of Johns Hopkins University, and he commented "Fahlberg is a scoundrel. It nauseates me to hear my name mentioned in the same breath with him." If you are interested in sweetener discovery stories, see The History of High Potency Sweeteners: Tales of Discovery.
Names
1,2-Benzisothiazol-3(2H)-one 1,1-dioxide 2,3-Dihydro-3-oxobenzisosulfonazole 1,2-Dihydro-2-ketobenzisosulfonazole Benzosulfimide o-Sulfobenzimide Benzoic sulfimide o-Sulfobenzoic acid imide Gluside Glucid Garantose Saccharinol Saccharinose Saccharol Saxin Sykose Hermestas Sodium salt: Soluble saccharin Saccharin sodium Kristallose Crystallose Dagutan Sucaryl Sucromat
Taste
Saccharin has a sweet taste; some people experience a bitter-metallic aftertaste. Its onset of sweetness is rapid. The sweetness potency relative to sucrose is about 300, but depends upon the concentration of sucrose which is being matched. The concentration vs. response relationship in water (results in food systems will vary) is shown below. This graph is based on data from DuBois, Walters, Schiffman, Warwick, Booth, Pecore, Gibes, Carr & Brands in "Sweeteners: Discovery, Molecular Design, and Chemoreception," D.E. Walters et al., Eds., American Chemical Society, 1991. The equation allows you to calculate sweetness response (R) for any concentration (C). The units of R are percent sucrose equivalent; the units of C are parts per million (ppm). The saccharin data were fit to a Hill-type equation (exponential).
Other links
© by D. Eric Walters