The invention includes a neutralized amino acid ester emulsifier, emulsions and compositions containing the emulsifier, and related methods. The emulsifier is a neutralized amino acid ester that is a reaction product of a neutral amino acid with a fatty alcohol and is represented by formula (I):wherein R1 is an alkyl group that has 6 to 24 carbon atoms； R2 is an alkyl group that has 6 to 36 carbon atoms； and the amine group of the amino acid is neutralized with an acid. The emulsifier is cationic. Also included are stable emulsions and compositions, preferably personal care compositions, that include the emulsifier and which may have pH levels of 5.5 or greater. Encompassed within the scope of the invention are methods of increasing the substantivity of a composition to a negatively charged substrate using the emulsifier, methods of emulsifying and methods of preparing a personal care composition using the emulsifier.
