Polyglycerol polyricinoleate, E476, is an emulsifier made in a three-step
process from glycerol and fatty acids. 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; 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. 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 soybean 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 anticlouding agent
in fractionated vegetable oils. In a 1998 review funded by Unilever of
safety evaluations from the late 1950s and early 1960s, "PGPR was found to be
98% digested by rats and utilized as a source of energy superior to starch and
nearly equivalent to groundnut oil." Additionally, no evidence was found of
interference with normal fat metabolism, nor with growth, reproduction, and
maintenance of tissue. Overall, it did not "constitute a human health hazard."
The Food and Drug Administration has officially deemed PGPR safe for human
consumption, setting the accepted daily intake from 0 to 7.5 milligrams per
kilogram of body weight. Short-term studies on rats and chickens showed
reversible liver enlargement as a result of higher doses of PGPR, but those were
deemed a result of increased hepatic workload.
Manufacture Glycerol is heated to above 200 °C in a
reactor in the presence of an alkaline catalyst to create polyglycerol. Castor
oil fatty acids are separately heated to above 200 °C, to create interesterified
ricinoleic fatty acids. The polyglycerol and the interesterified ricinoleic fatty
acids are then mixed to create PGPR. Use in chocolate candy bars
PGPR is used by chocolate makers to reduce their costs of raw materials.
Since 2006, commercial-grade candy bars, such as those made by Hersheys and
Nestlé, 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, such as Danisco and Palsgaard, indicate PGPR can
be used to replace the traditional but 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." However, the 1996 study conducted by
Andrew Waterhouse of UC Davis which discovered the phenols in chocolate also
revealed that these antioxidants come from cocoa butter and the stearic acid
it produces. It demonstrated that the phenols prevented LDL cholesterol from
building up in arteries. Another study had subjects follow diets in which the
majority of fat calories came from either chocolate or butter; only those
with the butterfat diet showed an increase in LDL cholesterol.
See also Compound chocolate
References External links
PGPR replacing cocoa butter in chocolate