Liquorice
| Liquorice | |
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| Species: | G. glabra
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| Glycyrrhiza glabra | |
Liquorice (Br.) or licorice (Am. and other Cw.) is the root of Glycyrrhiza glabra, from which a sweet flavour can be extracted. The liquorice plant is a legume related to beans and peas and native to southern Europe and parts of Asia. It is a herbaceous perennial plant growing to 1 m tall, with pinnate leaves 7–15 cm long with 9–17 leaflets. The flowers are 8–12 mm long, purple to pale whitish blue, produced in a loose inflorescence. The fruit is an oblong pod 2–3 cm long containing several seeds.
Cultivation and uses
- See main article on liquorice candy.
Liquorice is grown as a root crop mainly in southern Europe. Very little commercial liquorice is grown in North America, where it is replaced as a native species by the related American Licorice (G. lepidota), which has similar uses.
Liquorice extract is produced by boiling liquorice root and subsequently evaporating most of the water (in fact, the word 'liquorice' is derived from the Ancient Greek words for 'sweet root'). Liquorice extract is traded both in solid and syrup form. Its active principle is glycyrrhizin, a sweetener more than 50 times as sweet as sucrose which also has pharmaceutical effects. The related Chinese Liquorice (G. uralensis), which is used extensively in traditional Chinese medicine, contains this chemical in much greater concentration.
Liquorice flavor is found in a wide variety of liquorice candies. The most popular in the United Kingdom are very sweet Liquorice Allsorts. In continental Europe, however, far stronger, saltier, candies are preferred. It should be noted, though, that in most of these candies the taste is reinforced by aniseed oil, and the actual content of liquorice is quite low. Additionally, liquorice is found in some soft drinks, and is in some herbal teas where it provides a sweet aftertaste. The flavour is common in medicines to disguise unpleasant flavours.
Chinese cuisine uses liquorice as a culinary spice for savory foods. It is often employed to flavor broths and foods simmered in soy sauce.
Other herbs and spices of similar flavour include Anise, star anise, tarragon, and fennel.
Medicinal use
Powdered liquorice root is an effective cough remedy (expectorant), and has been used for this purpose since ancient times, especially in ayurvedic medicine where it is also used in tooth powders. Modern cough syrups often include liquorice extract as an ingredient. Additionally, licorice may be useful for both mouth ulcers [1] and peptic ulcers [2].
Liquorice is also a mild laxative. Large doses of glycyrrhizinic acid and glycyrrhetinic acid in liquorice extract can lead to hypokalemia and serious increases in blood pressure, a syndrome known as Apparent Mineralocorticoid Excess. These side effects stem from the inhibition of the enzyme 11β-hydroxysteroid dehydrogenase (type 1) and subsequent increase in activity of cortisol on the kidney. 11β-hydroxysteroid dehydrogenase normally inactivates cortisol in the kidney, thus licorice's inactivation of this enzyme makes the concentration of cortisol appear to increase. Cortisol acts at the same receptor as the hormone aldosterone in the kidney, thus the effects mimic aldosterone excess, although aldosterone remains low or normal during licorice overdose. Cortisol does not actually increase either, but its activity in the kidney does, due to the disabling of this enzyme. To decrease the chances of these serious side effects, deglycyrrhizinated licorice (DGL) preparations are available.
The disabling of similar enzymes in the gut by glycyrrhizinic acid and glycyrrhetinic acid also causes increased mucous and decreased acid secretion. Thus, licorice may in moderate amounts soothe an upset stomach and is used as an aid for healing stomach ulcers.
Though scientifically unproven, licorice has an ancient reputation as an aphrodisiac.