Polyglycerol polyricinoleate
（重定向自PGPR）
Polyglycerol polyricinoleate (PGPR), E476, is an emulsifier made in a three-step process from glycerol and fatty acids (usually castor bean derived). PGPR reduces the viscosity of chocolate and similar coatings and compounds. It works by decreasing the friction between the particles of cacao, sugar, milk, etc. present so they can flow more easily when melted. It can be used at low levels (below 1%); however, ingredients lists in chocolate are typically listed before the 2% and under section. This indicates it could be above 1% of the total product. It is made up of a short chain of glycerol molecules connected by ether bonds, with ricinoleic acid side chains connected by ester bonds.