Polyglycerol Polyricinoleate

Polyglycerol Polyricinoleate (PGPR), E476, is an emulsifier made from castor beans which 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 that they can flow more easily when melted. It is used at low levels (fractions of percents.)

Use in chocolate candy bars
It is primarily used to reduce the fat content of chocolate. Since 2006, commercial-grade candy bars, such as those made by Hersheys and Nestle, made an industry-wide switch to include PGPR as an ingredient - a possible indicator of a cost saving measure by the commercial chocolate industry. Makers of PGPR (see source link below) such as Danisco and Palsgaard indicate that PGPR can be used to replace the more expensive cocoa butter as an ingredient in chocolate. Palsgaard's website asserts, "Cocoa butter is an expensive raw material for chocolate manufacturers. By using PALSGAARD 4150 the chocolate recipe has lower costs in terms of less cocoa butter but also gives the benefit of having less fat."

PGPR is a yellowish, viscous liquid composed of polyglycerol esters of polycondensed fatty acids from castor oil. It may also be polyglycerol esters of dimerized fatty acids of soya bean oil.

PGPR is strongly lipophilic, soluble in fats and oils and insoluble in water and ethyl alcohol. In chocolates it is used as a viscosity reducing agent. It is virtually always paired with lecithin or another plastic viscosity-reducing agent.

It can also be used as an emulsifier in spreads and in salad dressings or as a crystal inhibitor and anti-clouding agent in fractionated vegetable oils.

The Vegan Society claims that PGPR may be animal-derived, but no evidence has been presented that any commercially available PGPR products are made using animal-derived substances.