This article is about the plant in the family Apiaceae cultivated for its seeds. For the plant in the family Lamiaceae cultivated for its leaves, see Plectranthus amboinicus.

Ajwain, ajowan[3] (/ˈædʒəwɒn/), or Trachyspermum ammi—also known as ajowan caraway, omam podi (in Tamil), thymol seeds, bishop's weed, or carom—is an annual herb in the family Apiaceae.[4] Both the leaves and the seed‑like fruit (often mistakenly called seeds) of the plant are consumed by humans. The name "bishop's weed" also is a common name for other plants. The "seed" (i.e., the fruit) is often confused with lovage "seed".[5]

Description

Ajwain fruit (schizocarps)

Ajwain's small, oval-shaped, seed-like fruits are pale brown schizocarps, which resemble the seeds of other plants in the family Apiaceae such as caraway, cumin and fennel. They have a bitter and pungent taste, with a flavor similar to anise and oregano. They smell almost exactly like thyme because they also contain thymol, but they are more aromatic and less subtle in taste, as well as being somewhat bitter and pungent. Even a small number of fruits tends to dominate the flavor of a dish.[5]

Cultivation and production

Ajwain tends to grow in regions that are dry and barren. This spice is indigenous to Egypt but is also grown in many parts of South & West Asia, including Iran, India, Pakistan, and other countries. Gujarat and Rajasthan are regions within India that are well known for cultivating ajwain.[6]

Culinary uses

The fruits are rarely eaten raw; they are commonly dry-roasted or fried in ghee (clarified butter). This allows the spice to develop a more subtle and complex aroma. It is widely used in the cuisine of the Indian subcontinent, often as part of a chaunk (also called a tarka), a mixture of spices – sometimes with a little chopped garlic or onion – fried in oil or clarified butter, which is used to flavor a dish at the end of cooking. It is also an important ingredient for herbal medicine practiced there. In Afghanistan, the fruits are sprinkled over bread and biscuits.[7]

Other application of ajwain include incorporating the seeds in specific types of breads, such as naans and parathas. The seeds can also be used as a mouth freshener when mixed with lemon juice and black pepper and then dried. Or, the seeds can simply be used as an ingredient in hot tea.[8]

As a medication

There is little high-quality clinical evidence that ajwain has anti-disease properties in humans.[9] Ajwain is sold as a dietary supplement in capsules, liquids, or powders.[9] An extract of bishop's weed is manufactured as a prescription drug called methoxsalen (Uvadex, 8-Mop, Oxsoralen) provided as a skin cream or oral capsule to treat psoriasis, repigmentation from vitiligo, or skin disorders of cutaneous T-cell lymphoma.[9][10] Because methoxsalen has numerous interactions with disease-specific drugs, it is prescribed to people only by experienced physicians.[10]

Ajwain is used in traditional medicine practices, such as Ayurveda, in herbal blends in the belief it can treat various disorders.[9][11] There is no evidence or regulatory approval that oral use of ajwain in herbal blends is effective or safe.[9]

Adverse effects

Women who are pregnant should not use ajwain due to potential adverse effects on fetal development, and its use is discouraged while breastfeeding.[9] In high amounts taken orally, bishop's weed is considered to be toxic and can result in fatal poisoning.[9]

Essential oil

Hydrodistillation of ajwain fruits yields an essential oil consisting primarily of thymol, gamma-terpinene, p-cymene, and more than 20 trace compounds which are predominantly terpenoids.[12]

References

  1. ^ "Trachyspermum ammi". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 11 December 2017.
  2. ^ ITIS entry for Trachyspermum ammi
  3. ^ "ajowan - Definition of ajowan in English by Oxford Dictionaries". Oxford Dictionaries - English.
  4. ^ "Ajwain". Digital Herbarium of Crop Plants. 4 October 2016. Retrieved 5 March 2021.
  5. ^ a b Aliza Green (January 2006). Field Guide to Herbs & Spices: How to Identify, Select, and Use Virtually Every Seasoning at the Market. Quirk Books. pp. 116–117. ISBN 978-1-59474-082-4.
  6. ^ Bairwa, Ranjan; Sodha, R. S.; Rajawat, B. S. (2012). "Trachyspermum ammi". Pharmacognosy Reviews. 6 (11): 56–60. doi:10.4103/0973-7847.95871. ISSN 0973-7847. PMC 3358968. PMID 22654405.
  7. ^ Alan Davidson (2014). The Oxford Companion to Food. Oxford University Press. pp. 9–. ISBN 978-0-19-967733-7.
  8. ^ "Health Benefits of Carom Seeds: The use of carom seeds in Indian cuisine, health benefits and culinary uses". The Times of India. 2021-07-01. Retrieved 2022-01-05.
  9. ^ a b c d e f g "Bishop's weed: Trachyspermum ammi L. Sprague". Drugs.com. 9 January 2018. Retrieved 21 November 2019.
  10. ^ a b "Methoxsalen (systemic)". Drugs.com. 6 October 2019. Retrieved 21 November 2019.
  11. ^ Duke, James A. (2002). Handbook of medicinal herbs. Duke, James A., 1929- (2nd ed.). Boca Raton, FL: CRC Press. ISBN 978-0849312847. OCLC 48876592.
  12. ^ Singh, Gurdip; Maurya, Sumitra; Catalan, C.; de Lampasona, M. P. (June 2004). "Chemical Constituents, Antifungal and Antioxidative Effects of Ajwain Essential Oil and Its Acetone Extract". Journal of Agricultural and Food Chemistry. 52 (11): 3292–3296. doi:10.1021/jf035211c. PMID 15161185.

External links