I think the first medicine I ever heard of was “Ricinus,” a liquidy concoction with which my mother plied me when she suspected I was constipated. I can’t imagine why as a child I would have had such a problem, since our diet in Hungary back then included generous doses of goose fat that should have allowed everything to slide through at a pretty regular pace.
Why, though, am I telling you about my youthful bowel habits? Because these memories were triggered by a question that has come up about a substance called “polyglycerol polyricinoleate” that appears on the label of some chocolate bars. As one might guess from the name, there is a connection to “Ricinus,” forged through the castor bean plant, botanically known as Ricinus communis. It is a pretty plant, sometimes grown ornamentally, but mostly cultivated for the seeds in its fruit that can be pressed to produce an oil for use in paints, glues, brake fluids and various lubricants. The same oil can also be used to produce polyglycerol polyricinoleate, an emulsifier that is now used extensively by chocolate manufacturers.
Chocolate lovers, of course, look for taste, but they also seek smoothness. A gritty product just won’t do. And therein lies a challenge. Chocolate is basically a mixture of cocoa butter, cacao particles, sugar and, in the case of milk chocolate, milk. The texture of the final product depends on how well these components can be blended together, which in turn depends on how effectively the friction between the ingredients can be reduced. This is where emulsifiers come in. These chemicals serve as internal lubricants, leading to a smoother consistency and easier flow when the chocolate is melted. That is of great importance when producing chocolate coatings.
The classic emulsifier used in chocolate manufacture has been lecithin, mostly derived from soy oil. But it is increasingly being replaced by polyglycerol polyricinoleate because of its greater effectiveness at reducing the viscosity of the chocolate and, perhaps more importantly, because it allows for less cocoa butter to be used and therefore makes for lower-fat chocolate. Increasing cocoa butter content increases smoothness, but cocoa butter is expensive. The use of polyglycerol polyricinoleate allows for the production of cheaper chocolate without sacrificing texture. Of course, consumers wonder if anything else is being sacrificed, such as safety. A virtually unpronounceable chemical name raises skepticism in many minds, especially when people discover that castor beans contain one of the most toxic natural substances known, a protein called ricin.
This chemical is so toxic that, prior to the First World War, the United States investigated its use as a coating for bullets. When ricin gets into the bloodstream it can kill in incredibly tiny doses. Since powdered ricin can be inhaled, it was investigated during the Second World War for possible use in cluster bombs. The Soviet KGB put ricin to a practical use, supplying the Bulgarian secret police with the tiny ricin-containing pellets that were used to assassinate dissident Georgi Markov in London in 1978 with a modified umbrella using compressed gas to fire the pellet. And today there is concern that terrorist groups are looking to extract ricin from castor seeds. But there is no need to worry about chocolate. Ricin is not soluble in fat at all and does not end up in the oil when the castor beans are pressed. And of course the polyglycerol polyricinoleate produced from the oil has undergone the stringent regulatory process required for a food additive. Pronouncing the complex term may be a challenge, but polyglycerol polyricinoleate can be consumed safely.
For me, castor oil conjures up memories of bitter taste. For some Italians, it might be a reminder of some bitter history. The expression “usare l’olio di ricino,” meaning “to coerce or abuse,” traces back to Benito Mussolini’s Fascist Blackshirts who forced political dissidents to drink large quantities of castor oil as a means of torture and humiliation. Since the victims were usually beaten as well, it was said that Mussolini’s power was backed by “the bludgeon and castor oil.”
It is unfortunate that castor oil’s name has been tainted in this fashion because the oil has a variety of important uses. The Blackshirts abused it, but in appropriate amounts, the oil can used to treat constipation and can also serve as a moisturizing agent for the skin. Industrially, castor oil can be reacted with compounds called isocyanates to yield polyurethanes, widely used plastics. Automobile manufacture uses large quantities of polyurethanes, which traditionally have been made from petroleum derivatives. Castor oil is a renewable resource so it provides for a “greener” process.
The oil can also be converted into lithium 12-hydroxystearate, a high performance lubricant grease, as well as into sebacic acid, used in the production of a type of nylon. The oil itself is an effective lubricant and was widely used in the rotary engines of Allied airplanes in the First World War and is still used to lubricate model airplane engines as well as race car engines. The Castrol Company that produces various lubricants derives its name from castor oil, which in turn gets its name from the Latin “castor” for beaver. That’s because of its use as a replacement for “castoreum,” an extract of the perineal glands of the beaver. Beavers use castoreum as a territorial marker, but cosmetic chemists have found that adding it to perfumes maintains the fragrance for a longer time. Castor oil can act similarly, but is cheaper to produce.
While the oil will lengthen the time before a fragrance evaporates, it won’t lengthen eyelashes, despite the claims of some “holistic” practitioners, one of whom told me that beavers have shiny, long fur, so castor oil will do the same for eyelashes. This is where our funny bone gets tickled. “Castor” is beaver in French. This ill-informed practitioner thinks that castor oil comes from beavers, perhaps conjuring up some mental image of the animals being squeezed to extract their oil.
