The artificial sweetener in Splenda is sucrose (figure 6), which is more or less 1,000 times sweeter than sugar. Unfortunately, in the proton NMR spectrum we cannot see the sucrose present in Splenda due to the small amount present and probably most of the signals are buried under the glucose peaks as well.
The main sweetener in Equal is aspartame, but it also contains acesulfame potassium (figure 6). Both sweeteners are roughly 200 times sweeter than sugar. Acesulfame potassium is blended with aspartame in order to improve the overall taste of the sugar substitute. The combination of these two compounds gives a more sugar-like taste. If you pay close attention to the spectrum of Equal, you will be able to see tiny peaks around 2.0, 2.5 and 7.4 ppm, which correspond to the aspartame and acesulfame potassium present in the sweetener!
Stevia is a sweetener extracted from the leaves of Stevia rebaudiana, which is native to the Amambay Cordillera in Northeast Paraguay. [5] When we think of Stevia most of the time we think of a single component forming this natural sweetener, but this is wrong! There are actually several compounds that form Stevia and they belong to a family called steviol glycosides. For that reason, most of the time the main ingredient listed for Stevia is “Stevia leaf extract”. Some of the steviol glicosides extracted from stevia rebaudiana are: stevioside, Rebaudioside A, Rebaudioside C, and Dulcoside A. However, stevioside is present in the highest weight percent. If we look at the Stevia spectrum in Figure 3, we can see a small bump around 5.50 ppm, which is very close to the chemical shift of the glycosidic proton of sucrose. If you thought there was sucrose present in Stevia you were wrong, but not totally wrong. A glycoside unit is part of stevioside (figure 7) and its glycosidic proton shows at 5.50 ppm. Giving the similar chemical environments of the glycosidic proton of sucrose and glycoside unit in stevioside, it’s not surprising that their chemical shifts are so similar.