https://www.cnchemsino.com/products/pgms/pgms40.html Propylene Glycol Esters is a lipophilic food additive obtained by esterification of propylene glycol with stearic acid followed by distillation.It is a multi-purpose emulsifier.Propylene glycol esters has good foaming and emulsifying properties. Its foaming ability depends on the monoester content. The higher the monoester content, the better the performance. It is often used as a foaming agent for cakes and butter cakes, and is also often used in conjunction with mono- and di-fatty acid glycerides for synergistic effects.