Emulsifier is a kind of surfactant that stabilizes emulsions.The function of an emulsifier is when it is dispersed on the surface of a dispersed substance, a thin film or electric double layer is formed, which can make the dispersed phase carry a charge; that can prevent small droplets of the dispersed phase from coagulating, thereby creating a stable emulsion. For example, add a certain amount of emulsifier to solid pesticide solid or liquid crude oil, then dissolve them in an organic solvent, and mix them evenly to make a transparent liquid called emulsifiable concentrate.
Non-ionic surfactant is a common emulsifier. Non-ionic surfactant with higher HLB values are more suitable for preparing O/W emulsifiers; whereas ones with lower HLB values are more suitable for preparing W/O emulsifiers. Natural oil water emulsifiers are mostly hydrophilic gums, which can improve the viscosity of continuous phase and increase the stability of emulsions. They are suitable for the preparation of O/W emulsifiers, solid particulate emulsifiers and auxiliary emulsifiers.
Food emulsifiers have the largest demand for fatty acid monoglyceride, followed by sucrose ester, sorbitan ester, soybean phospholipid, monoglyceride laurate, propylene glycol fatty acid ester etc.
Sorbitan esters were developed early and has been used in the food industry for decades. Their annual consumption amount is about 10% of the total consumption of food emulsifiers.