aspartame UK /əˈspɑːteɪm/US /ˈæspɚˌteɪm/ noun1 •An artificial sweetener, the methyl ester of a dipeptide formed from aspartic acid and phenylalanine, used in many processed foods and beverages.Caramel colors and aspartame Phosphoric acid, potassium Natural flavors, of course caffeine And now I'm jonesin' for MSG — 2006 formsaspartames