I. GENERAL
COMMON NAME
Wormwood
BOTANICAL NAME
Artemisia absinthism L.
FAMILY
Compositae
OTHER NAMES
Absinthe, Mugwort (USA), Common Wormwood
CULTIVATION CONDITIONS
The plant is indigenous to North America, Southern Europe, North America and North-West Asia. It is usually found with associated species Artemisia alba, Artemisia annua and Artemisia vulgaris. It has also been cultivated in France, Yugoslavia, Holland, Belgium and Hungary in the peppermint and spearmint growing areas. The herbaceous plant is a perennial growing from 60 - 120 cms tall. The oil is distilled from the dried leaves and flowering tops of the herb (Guenther).
MAJOR PRODUCING COUNTRIES
United States, Morocco and the USSR, USA (5 tonnes), Brazil (1 tonne), Hungary (150 kg), Bulgaria (700 kg), Morocco and USSR (no identifiable figures)
YIELD AND DESCRIPTION
It is dark green to brownish in colour with a herbaceous distilled odour and a bitter taste but in high dilution is reminiscent of hops and chamomile. The colour is attributed to azulene (Arctander).
Various reported yields indicate the average yield is 0.35% of semi-dried herb. While the life of the plant is 7 - 10 years, the best yields are in the second and third years and the plants are rarely kept after 4 - 5 years.
MAIN USES
The oil has several names (Wormwood oil, Essence d'Absinthe, Oil of Mugwort (USA), Common Wormwood Oil) and is used as the flavouring of "Absinth", and its subsequent ban by the French government, is widely reported (Arctander). The whole oil and distilled fractions are used as the flavouring principle of Vermouth. According to Merck it has therapeutic properties as an anthelmintic and antimalarial, but Guenther warns it is an active narcotic poison (Guenther). Wormwood Oil should not be confused with American Wormseed Oil (Chenopodium ambrosiodes var. anthelminthicum L.) or Chenopodium Oil (Chenopodlum ambrosiodes)
II. AGRICULTURAL ASPECTS
CULTIVATION
A typical planting density is 25,000 plants / Ha. Seeds can either be planted direct in late autumn or in greenhouses in early spring, from slips or from root division. The plants are very hardy and resistant to disease or insects, however, weed control in the first season, is important.
Weedkillers used for mint are satisfactory for Wormwood. This herb responds well to fertilizers (Slepetys) and it can be used for the reclamation of sandy soils (Glavan). It has been shown that a 50% increase in oil content was achieved at an altitude increase from 0 to 1000 metres (Alekseev).
HARVESTING PERIOD
In the northern hemisphere the plant is harvested when in full bloom, usually in July, for best oil quality and quantity.
HARVESTING METHODS
By the use of a forage harvester.
III. POST HARVEST, TREATMENT, PRESERVATION, STORAGE
PRE-TREATMENT
The herb should be wilted for 24 hours before distillation.
PRESERVATION
Antioxidant can be added to the oil.
STORAGE
The oil should be stored in full, well-sealed containers.
IV. PROCESSING
PROCESSING METHOD
While field stills can be used, modern distillation equipment, such as that used for mint processing, is preferable. The best oil is obtained from direct steam applications, rather than water distillations. Distillation appears complete after 2 hours, but is continued for an extra half hour to collect some heavy fractions.
COMPOSITION OF OIL
The main constituent of the oil is reported to be Thujone. The E.O.A. specification (EOA) gives a ketone content of 34 - 71% calculated as Thujone. A recent study reports on the chemical analysis of the oil from Patagonia (Sacco).
EQUIPMENT
Forage harvester
Steam distillation equipment
Steam boiler
There is no identifiable information for the following areas: PROCESSING oil extraction, and nomenclature of products.
BIBLIOGRAPHY
ARCTANDER, S. "Perfume and Flavour Materials of Natural Origin". (Private publication)
GUENTHER, E. "The Essential Oils" Vol 5 'Oil of Wormwood' ISBN no 0-88275-163-8
LAWRENCE, B.M. "Progress in Essential Oils" 'Perfumer and Flavorist' April/May 1981 Vol 6 No. 2 p 59
"The Merck Index" Tenth Edition ISBN No 911910-27-1
SLEPETYS, J. "The Biology and Biochemistry of Wormwood". 2 "The Effects of Fertiliser on the Concentration and Yield of Essential Oil. (Artemisia absinthism)" Akad Nauk Litov Ssr Darbai Tr Ser C 1970, 3: pp 33 - 40 (In Russian with English summary.
SLEPETYS, J. "The Biology and Biochemistry of Wormwood". 5. "Effect of different Norms of Mineral Fertilisers on the Yield and Amount of Essential Oil (Artemisia absinthism)" Darb, C Ser Biol Mokslaij Liet TSR Mokslu Akad 1973, 3: pp 29 - 35 ( In Russian) Artemisia absinthism L.
ALEKSEEV, B.D; SHLEIFER, G.A; "Essential Oil content of some Artemisia. Species of the Dagestan Flora".Rastitelnye Resursy 1983, 19: 3, pp 360 - 364
E.O.A No 114 "Oil Wormwood" Scientific Section Essential Oil Association of U.S.A.
GLAVAN, P; BURNEA, I; PLENICEANU, M; RUSU, O.; CHICHEA, I; Reclamation of Sandy soils for cultivation of Medicinal Plants". Analele universitatis Craiova Biol Agron Hortic 1985 16 pp 101 - 112 (In Romanian, French Summary).
SACCO, T; CHIALVA, F; "Chemical Characteristics of the Oil from Artemisia absinthism collected in Patognia, Argentina. " Planta Medica 1988, 54: 1, p 93
Appendix I - Summary of various applications of minor essential oil crops
The following Table shows the distribution of various known applications of extracted fatty materials from those minor essential oil crops, reviewed in this section. Such applications are listed below:
A. MAJOR APPLICATIONS
B. MINOR APPLICATIONS