Liquorice

Liquorice (Commonwealth English) or licorice (American English; see spelling differences; Template:IPAc-en Template:Respell) is the common name of Glycyrrhiza glabra, a flowering plant of the bean family Fabaceae, from the root of which a sweet, aromatic flavouring is extracted.

The liquorice plant is an herbaceous perennial legume native to West Asia, North Africa, and Southern Europe. Liquorice is used as a flavouring in confectionery, tobacco, beverages, and pharmaceuticals, and is marketed as a dietary supplement.

Liquorice extracts have been used in herbalism and traditional medicine. Excessive consumption of liquorice (more than Template:Cvt per day of pure glycyrrhizinic acid, a key component of liquorice) can lead to undesirable consequences. Clinically, it is suspected that overindulgence in liquorice may manifest as unexplained hypertension, low blood potassium levels (hypokalemia), and muscle weakness in individuals. Consuming liquorice should be avoided during pregnancy.

Etymology

The word liquorice (UK, CAN), or licorice (US), is derived via the Anglo-French , from Late Latin , itself ultimately derived from Greek Template:Langx (the Modern Greek spelling of the genus is Template:Langx) literally meaning 'sweet root' and referring to Glycyrrhiza glabra.

The latter gives the plant binomial name with glabra meaning smooth and referring to the plant's smooth husks; the former came to being via the influence of , 'to become fluid', reflecting the method of extracting the sweet component from the roots.

Template:As of, its English common name is spelled 'liquorice' in most of the Commonwealth, but 'licorice' is also used in some countries.

Description

Liquorice is a herbaceous perennial, growing to Template:Convert in height, with pinnate leaves about Template:Cvt long, with 9–17 leaflets. The flowers are Template:Cvt long, purple to pale whitish blue, produced in a loose inflorescence. The fruit is an oblong pod, Template:Cvt long, containing several seeds. The roots are stoloniferous.

Chemistry

File:Glycyrrhizic Acid.svg

Much of the sweetness in liquorice comes from glycyrrhizin.

File:Sections of liquorice root.jpg

Sections of liquorice root

Liquorice root contains triterpenoids, polyphenols, and polysaccharides. Flavonoids account for the yellow root color. The principal glycoside, glycyrrhizin, exists in content of 7% to 10%, depending on cultivation practices. The isoflavene glabrene and the isoflavane glabridin, found in the roots of liquorice, are phytoestrogens.

The scent of liquorice root comes from a complex and variable combination of compounds, of which anethole is some 3% of total volatiles. Much of the sweetness in liquorice comes from glycyrrhizin, which has 30–50 times the sweetness of sugar. The sweetness is different from sugar, being less instant, tart, and lasting longer.

Cultivation and uses

Liquorice grows best in well-drained soils in deep valleys with full sun. It is harvested in the autumn two to three years after planting. Countries producing liquorice include Turkey, Greece, Iran, and Iraq.

Tobacco

Liquorice is used as a flavouring agent for tobacco, for flavour-enhancing and moistening agents in the manufacture of American blend cigarettes, moist snuff, chewing tobacco, and pipe tobacco. Liquorice provides tobacco products with a natural sweetness and a distinctive flavour that blends readily with the natural and imitation flavouring components employed in the tobacco industry. Liquorice can also be added to cigarette rolling papers. Template:As of, the US Food and Drug Administration banned the use of any "characterizing flavors" other than menthol from cigarettes, but not other manufactured tobacco products.

Food and confectionery

File:Baton de reglisse.jpg

Dried sticks of liquorice root

Liquorice flavour is found in a wide variety of candies or sweets. In most of these candies, the taste is reinforced by aniseed oil so the actual content of liquorice is low.

In the Netherlands, liquorice confectionery (drop) is a common sweet sold in many forms. Mixing it with mint, menthol, aniseed, or laurel is common. It is also mixed with ammonium chloride (); salmiak liquorice in the Netherlands is known as ('salty liquorice'). Strong, salty sweets are also consumed in Nordic countries where liquorice flavoured alcohols are sold, particularly in Denmark and Finland.

Dried sticks of the liquorice root are a traditional confectionery in the Netherlands as were they once in Britain. They were sold simply as sticks of ('sweet wood') to chew on as a candy.

File:Liquiritiae radix suessholzwurzel.jpg

Liquorice root chips

Pontefract in Yorkshire, England, is where liquorice mixed with sugar began to be used as a sweet in the contemporary way. Pontefract cakes were originally made there. In Cumbria, County Durham, Yorkshire and Lancashire, it is colloquially known as 'Spanish', supposedly because Spanish monks grew liquorice root at Rievaulx Abbey near Thirsk.

In Italy, Spain, and France, liquorice is used in its natural form. The root of the plant is simply harvested, washed, dried, and chewed as a mouth freshener. Throughout Italy, unsweetened liquorice is consumed in the form of small black pieces made only from 100% pure liquorice extract. In Calabria, a liqueur is made from pure liquorice extract and in Reggio Emilia a soft drink called acqua d'orcio is made. In some parts of the Arab world, including Egypt and the Levant, the root of the licorice plant is used to make a cold drink with a sweet and mildly bitter taste, called Erk al-sous. This beverage is especially popular during Ramadan.

In southeastern Turkey, such as in Diyarbakır, licorice root is traditionally made into a chilled beverage that is most commonly consumed in summer.

Research

Properties of glycyrrhizin are under preliminary research, such as for hepatitis C or topical treatment of psoriasis, but the low quality of studies Template:As of prevents conclusions about efficacy and safety.

Traditional medicine

In traditional Chinese medicine, a related species G. uralensis (often translated as "liquorice") is known as Template:Transliteration (Template:Zh), and is believed to "harmonize" the ingredients in a formula. although there is no high-quality clinical research to indicate it is safe or effective for any medicinal purpose. The European Medical Agency added liquorice to their list of herbal medicine.

Fungicide

The essential oils inhibit the growth of Aspergillus flavus.

Adverse effects

Consumption levels

The United States Food and Drug Administration regards that foods containing liquorice and its derivatives (including glycyrrhizin) are generally recognized as safe for use as a food ingredient, if not consumed excessively. Other jurisdictions have suggested no more than Template:Convert of glycyrrhizin per day, the equivalent of about Template:Convert of liquorice confectionery. Although liquorice is considered safe as a food ingredient, glycyrrhizin can cause serious side effects if consumed in large amounts (above 0.2 mg per kg per day). One estimate is that a normal healthy person can consume Template:Convert of glycyrrhizic acid per day.

Because the composition of liquorice extracts in various products may exist in a broad range, there is not enough scientific information to determine that a specific level of intake is safe or unsafe.

Physiological effects

The effects of excessive liquorice consumption on lowering potassium levels in the blood and increasing blood pressure are a particular concern for people with hypertension (high blood pressure) or heart or kidney disease.

Some adverse effects of liquorice consumed in amounts of 50 to 200 g per day over four weeks appear to be caused by glycyrrhizic acid (75 to 540 mg per day glycyrrhetinic acid) causing increases in blood pressure. Consuming large amounts of liquorice during pregnancy has been associated with premature birth and health problems in the child.

Hyper-mineralocorticosteroid syndrome can occur when the body retains sodium, and loses potassium, altering biochemical and hormonal regulation. Some of these activities may include raised aldosterone levels, decline of the renin-angiotensin system and increased levels of the atrial natriuretic hormone in order to compensate the variations in homoeostasis.

Other adverse effects may include electrolyte imbalance, edema, increased blood pressure, weight gain, heart problems, and weakness. Symptoms depend on the severity of toxicity. Some other complaints include fatigue, shortness of breath, kidney failure, and paralysis.

Potential for toxicity

The major dose-limiting toxicities of liquorice are corticosteroid in nature, because of the inhibitory effect that its chief active constituents, glycyrrhizin and enoxolone, have on cortisol degradation, and include edema, hypokalaemia, weight gain or loss, and hypertension.

Gallery

• Liquorice root with bark
  Liquorice root with bark
• Inflorescence of G. glabra
  Inflorescence of G. glabra
• Various liquorice products
  Various liquorice products
• Different flavoured liquorice sticks
  Different flavoured liquorice sticks
• Foliage
  Foliage
• G. glabra from Koehler's Medicinal-Plants
  G. glabra from Koehler's Medicinal-Plants

External links

• Template:Cite EB1911
• Glycyrrhiza glabra (licorice), Kew plant profile
• What's That Stuff?: Licorice, Chemical & Engineering News