 | |
| Names | |
|---|---|
| IUPAC name 1,2,3-Propanetriol, homopolymer, (9Z,12R)-12-hydroxy-9-octadecenoate | |
| Identifiers | |
| ChemSpider |
|
| ECHA InfoCard | 100.117.614 |
| E number | E476(thickeners, ...) |
| UNII | |
| Properties | |
| (C3H5O2)n(C18H32O2)m | |
| Related compounds | |
Related compounds |
|
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Polyglycerol polyricinoleate (PGPR),E476, is anemulsifier made fromglycerol and fatty acids (usually fromcastor bean, but also fromsoybeanoil). Inchocolate,compound chocolate and similar coatings, PGPR is mainly used with another substance likelecithin[2] to reduceviscosity. It is used at low levels (below 0.5%),[3][4] and works by decreasing thefriction between the solid particles (e.g.cacao,sugar,milk) in molten chocolate, reducing theyield stress so that it flows more easily, approaching the behaviour of aNewtonian fluid.[4] It can also be used as an emulsifier inspreads and insalad dressings,[5] or to improve the texture of baked goods.[5] It is made up of a short chain of glycerol molecules connected byether bonds, withricinoleic acid side chains connected byester bonds.
PGPR is a yellowish,viscous liquid, and is stronglylipophilic: it is soluble in fats and oils and insoluble in water andethanol.[3]
Glycerol is heated to above 200 °C in a reactor in the presence of analkaline 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.[6]
As PGPR improves the flow characteristics of chocolate andcompound chocolate, especially near the melting point, it can improve the efficiency of chocolate coating processes: chocolate coatings with PGPR flow better around shapes ofenrobed and dipped products,[7][8] and it also improves the performance of equipment used to produce solid molded products:[8] the chocolate flows better into the mold, and surrounds inclusions and releases trapped air more easily.[2] PGPR can also be used to reduce the quantity ofcocoa butter needed in chocolate formulations: the solid particles in chocolate are suspended in the cocoa butter, and by reducing the viscosity of the chocolate, less cocoa butter is required,[2] which saves costs, because cocoa butter is an expensive ingredient, and also leads to a lower-fat product.[9]
TheFDA has deemed PGPR to begenerally recognized as safe for human consumption,[1] and theJoint FAO/WHO Expert Committee on Food Additives (JECFA) has also deemed it safe.[3] Both of these organisations set theacceptable daily intake at 7.5 milligrams per kilogram of body weight. In 2017, a panel from theEuropean Food Safety Authority recommended an increased acceptable daily intake of 25 milligrams per kilogram of body weight based on a new chronictoxicity andcarcinogenicity study.[10] In Europe, PGPR is allowed in chocolate up to a level of 0.5%.[3]
In a 1998 review funded byUnilever 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 tostarch and nearly equivalent topeanut oil."[11] 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".[11]
A study published in the European Food Safety Authority in 2017 re-evaluated the safety of the additive and recommended to revise the acceptable daily intake and increase it to 25 milligrams per kilogram of body weight.[12]
