Wednesday, January 1, 2014

Sweeteners' sweetness asymptotes at different levels

To make a cup of Coca-Cola, you’d need... about six teaspoons’ worth of sugar, for a 10.4 percent solution. (Pepsi is a little sweeter, at 11 percent. Root beers and some fruit-flavored sodas can be 12 percent or more.) That’s where many [sugar] substitutes fall short.

[Flavor chemist Grant] DuBois had a set of graphs tracking how the power of a sweetener changes with its concentration. He included curves for six different compounds, from saccharin to stevia, but they all looked very much the same. Each curve rose steeply, gaining sweetness with every increment in milligrams per liter, then appeared to hit a ceiling, a point at which the sweetness flattened out. Once you reach that threshold concentration, a compound loses its effect: No matter how much more of it you pump into a beverage, you’ll never get a sweeter taste. The ceilings for some chemicals are high enough to flavor carbonated drinks. Aspartame, for example, can match the taste of sugar in a 16 percent solution. But others reach their limit much too soon. That’s why today you’ll never find a Diet Coke that’s made with saccharin. At best it would match the sweetness of a sugar drink at 10.1 percent.
--Daniel Engber, NYT Magazine, on the mysteries of flavor chemistry