A DELICATE PROBLEM
Turkish treat puts orchids at risk
Who would have thought that a love of ice cream could be driving some varieties of orchids toward extinction? Not any ice cream, mind you, but a special variety favoured mostly in Turkey, called “dondurma,” which in Turkish means “freezing.”
Dondurma is more resistant to melting than our ice cream and has a thicker, stretchy consistency, as well as a characteristic flavour. The texture and flavour are mostly from the inclusion of the hardened sap of the mastic tree that grows mostly on the Greek Island of Chios. The sap hardens into a resin composed of a complex mixture of simple carbohydrates and polysaccharides that can impart an elastic texture when pressure is applied artificially or by chewing. Indeed, the name “mastic” for the tree derives from the Greek verb for “gnashing the teeth,” which also is the source of our English word “masticate.”
Mastic resin also contains a variety of compounds in the terpene family that provide a unique pine-like flavour and aroma. Besides ice cream, the resin is also added to puddings, sauces, Turkish delight, perfumes and body lotions. It is a relatively expensive commodity because of the rarity of the mastic trees.
The exudate of the mastic tree has a history of use as a medicine, as well. The ancient Greek physicians Dioscorides, Hippocrates and Galen all mention the medicinal properties of mastic, mostly for colds and digestive problems.
While an effect on colds is questionable, there may actually be something concerning digestive issues. A few studies have shown that compounds in mastic have antibacterial properties and can have an effect on peptic ulcers by killing Helicobacter pylori bacteria. They may also reduce tooth decay by diminishing the population of oral microbes that secrete acids. There are also stories about mastic extracts being used as breath fresheners in the harems of sultans in the Middle Ages. Whether the resin was chewed by the sultan or his ladies isn’t clear.
The resistance to melting is mostly from the addition of “salep,” which is flour made from the roots of a genus of orchid. Its main component is “glucomannan,” a form of dietary fibre composed of glucose and mannose molecules joined in long chains. It has a remarkable ability to absorb water, which means it can keep ice cream firm even when it is melting. This is also the reason glucomannan has been marketed as a diet aid.
Unlike digestible carbohydrates such as starch, glucomannan is resistant to breakdown by our salivary or pancreatic enzymes. As a dose of indigestible glucomannan sits in the stomach or small bowel before passing on to the colon, it absorbs a great deal of water. This bulky mélange of water and fibre makes for a feeling of fullness and curbs the appetite.
A few short-term studies have shown more efficient weight loss on a low calorie diet that incorporates about four grams of glucomannan per day. However, a number of companies have hyped glucomannan supplements, mostly extracted from the tubers of the konjac plant, way beyond what research has shown.
Like mastic resin, salep has a long history of folkloric use. Sixteenth-century philosopher and physician Paracelsus believed that nature bestowed specific shapes on plants to mark their curative benefits. This eventually became known as the “doctrine of signatures,” based on German theologian Jakob Bohme’s claim that God had marked objects with a “signature” to give clues about their purpose. Parts of plants or animals that resembled human body parts were thought to have a beneficial effect on those parts. Paracelsus suggested orchid roots, when ingested, would restore a man’s virility and passion because they resembled the male testes. That theory, however, is soft on evidence.
In the 17th century, beverages made from salep became popular in England, possibly because of the aphrodisiac connotation. However, British orchid roots, known as “dogstones” were often substituted for salep. While the consumption of salep in England has faded, in Turkey, drinks and ice cream made from orchid flour are increasing in popularity. This is bad news for orchids, since it takes a couple of thousand tubers to produce a kilo of salep.
Orchids are difficult to cultivate on farms and the main supply is wild orchids. Harvesting these has raised the spectre of local extinctions, not only in Turkey, but in Africa and Iran as well, with millions of tubers being illegally harvested for export to Turkey. This is disturbing, especially given that glucomannan is available from konjac root, and indeed, in Turkey producers are turning to this instead of using orchids.
Still, there is the cachet of the traditional process that is hard to overcome. Researchers are working on ways to culture orchid seeds in the lab with hopes of developing seedlings that can be commercially cultivated. That, then, may lick the Turkish ice cream problem.