Diet Coke
Diet Coke does not use a modified form of the Coca-Cola recipe, but instead an entirely different formula. The controversial New Coke, introduced in 1985, used a version of the Diet Coke recipe that contained high fructose corn syrup and had a slightly different balance of ingredients. In 2004, Coca-Cola introduced Coca-Cola C2, which it claims tastes much closer to Coca-Cola but contains half the carbohydrates. In 2005, the company introduced Coca-Cola Zero (replaced by "Coca-Cola Zero Sugar" in 2017), a sugar-free variation of regular Coca-Cola.
Acesulfame potassium
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.