Glycerol ester of wood rosin

Glycerol ester of wood rosin, also known as glyceryl abietate or ester gum, is an oil-soluble food additive (E number E445). The food-grade material is used in foods, beverages, and cosmetics to keep oils in suspension in water, and its name may be shortened in the ingredient list as glycerol ester of rosin. It is also used as an ingredient in the production of chewing-gum and ice cream. Similar, less pure materials (glycerol ester of gum rosin) are used as a component of certain low-cost adhesives.
To make the glycerol ester of wood rosin, refined wood rosin is reacted with glycerin to produce the glycerol ester. 
Glycerol ester of wood rosin is an alternative to brominated vegetable oil in citrus oil-flavored soft drinks. In some cases, both ingredients are used together.