View source for Kaffir lime

{{Short description|Citrus fruit native to tropical Southeast Asia}}
{{Speciesbox
|image = Citrus hystrix fruit.jpg
|image_caption = Fruit on tree
|range_map = Map of inferred original wild ranges of the main Citrus cultivars, and selected relevant wild taxa (Fuller et al., 2017).png
|range_map_caption = Map of inferred original wild ranges of the main ''Citrus'' cultivars, with ''C. hystrix'' in pale green<ref name="fuller">{{cite book|first1=Dorian Q. |last1=Fuller |first2=Cristina |last2=Castillo |first3=Eleanor|last3=Kingwell-Banham|first4=Ling|last4=Qin|first5=Alison|last5=Weisskopf|editor1-first=Véronique |editor1-last=Zech-Matterne |editor2-first=Girolamo|editor2-last=Fiorentino|title =AGRUMED: Archaeology and history of citrus fruit in the Mediterranean |chapter =Charred pomelo peel, historical linguistics and other tree crops: approaches to framing the historical context of early Citrus cultivation in East, South and Southeast Asia |publisher =Publications du Centre Jean Bérard|year =2017|pages=29–48|isbn =978-2-918887-77-5|doi=10.4000/books.pcjb.2107|url=https://hal.archives-ouvertes.fr/hal-03501166/file/2017-Ruas-etal-Citrus.pdf |chapter-url =https://books.openedition.org/pcjb/2173?lang=en}}</ref>
|genus = Citrus
|species = hystrix
|authority = [[Augustin Pyramus de Candolle|DC.]]<ref name=tpl>{{ cite web |url=http://www.theplantlist.org/tpl/record/kew-2724129 |title=TPL, treatment of ''Citrus hystrix'' DC. |work=[[The Plant List]]; Version 1. (published on the internet) |publisher=[[Royal Botanic Gardens, Kew]] and the [[Missouri Botanical Garden]] |year=2010 |access-date=March 9, 2013}}</ref>
|synonyms =
    {{Plainlist | style = margin-left: 1em; text-indent: -1em; |
*''C. auraria'' <small>Michel</small>
*''C. balincolong'' <small>(Yu.Tanaka) Yu.Tanaka</small>
*''C. boholensis'' <small>(Wester) Yu.Tanaka</small>
*''C. celebica'' <small>Koord.</small>
*''C. combara'' <small>Raf.</small>
*''C. echinata'' <small>St.-Lag.</small> nom. illeg.
*''C. hyalopulpa'' <small>Yu.Tanaka</small>
*''C. kerrii'' <small>(Swingle) Tanaka</small>
*''C. kerrii'' <small>(Swingle) Yu.Tanaka</small>
*''C. latipes'' <small>Hook.f. & Thomson ex Hook.f.</small>
*''C. macroptera'' <small>Montrouz.</small>
*''[[Citrus micrantha|C. micrantha]]'' <small>Wester</small>
*''C. papeda'' <small>Miq.</small>
*''C. papuana'' <small>F.M.Bailey</small>
*''C. southwickii'' <small>Wester</small>
*''C. torosa'' <small>Blanco</small>
*''C. tuberoides'' <small>J.W.Benn.</small>
*''C. ventricosa'' <small>Michel</small>
*''C. vitiensis'' <small>Yu.Tanaka</small>
*''C. westeri'' <small>Yu.Tanaka</small>
*''Fortunella sagittifolia'' <small>K.M.Feng & P.Y.Mao</small>
*''Papeda rumphii'' <small>Hassk.</small>
    }}
|synonyms_ref = <ref>{{citation
|url=http://www.theplantlist.org/tpl1.1/record/kew-2724129
|title=The Plant List: A Working List of All Plant Species
|access-date=3 October 2015}}</ref>
}}

'''''Citrus hystrix''''', called the '''kaffir lime''', '''Thai lime'''<ref name=":0" /> or '''makrut lime''',<ref>{{citation |title=A classification for edible ''Citrus'' (Rutaceae) |author=D.J. Mabberley |year=1997 |journal=Telopea |volume=7 |issue=2 |pages=167–172 |doi=10.7751/telopea19971007 |doi-access=free }}</ref> ({{IPAc-en|US|ˈ|m|æ|k|r|@|t}}, {{IPAc-en|UK|m|ə|k|ˈ|r|uː|t}})<ref name="grin">{{GRIN | access-date=December 7, 2014}}</ref> is a [[citrus fruit]] native to [[tropical Asia|tropical]] [[Southeast Asia]].<ref name="npark">{{cite web |title=''Citrus hystrix'' |url=https://florafaunaweb.nparks.gov.sg/Special-Pages/plant-detail.aspx?id=3670 |website=Flora & Fauna Web |publisher=National Parks Singapore, Singapore Government |access-date=13 August 2018}}{{Dead link|date=July 2021}}</ref><ref>{{cite web |title=''Citrus hystrix'' |url=http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=291778&isprofile=0& |website=Plant Finder |publisher=Missouri Botanical Garden |access-date=13 August 2018}}</ref>

Its fruit and leaves are used in [[Southeast Asian cuisine]], and its [[Petitgrain|essential oil]] is used in perfumery.<ref name=Ng>{{cite journal |author1=Ng, D.S.H. |author2=Rose, L.C. |author3=Suhaimi, H. |author4=Mohamad, H. |author5=Rozaini, M.Z.H. |author6=Taib, M. |year=2011 |title=Preliminary evaluation on the antibacterial activities of ''Citrus hystrix'' oil emulsions stabilized by TWEEN 80 and SPAN 80 |journal=International Journal of Pharmacy and Pharmaceutical Sciences |volume=3 |issue=Suppl. 2 |url=http://www.ijppsjournal.com/Vol3Suppl2/2007.pdf |access-date=2014-12-10 |archive-date=2018-04-12 |archive-url=https://web.archive.org/web/20180412213816/http://ijppsjournal.com/Vol3Suppl2/2007.pdf }}</ref> Its rind and crushed leaves emit an intense citrus fragrance.

==Names==
[[File:Citrus hystrix Blanco2.408-cropped.jpg|thumb|left|upright|Illustration of ''C. hystrix'' by [[Francisco Manuel Blanco]]]]

The most likely [[etymology]] is through the [[Sri Lanka Kaffirs|Kaffirs]], an ethnic group in [[Sri Lanka]] partly descended from enslaved [[Bantu peoples|Bantu]].<ref name="Slate 140703">{{cite web |last1=Anderson |first1=L. V. |title=Is the Name Kaffir Lime Racist? Why You May Want to Think Twice About Using That Term. |url=https://slate.com/culture/2014/07/kaffir-lime-racist-murky-origins-suggest-a-racial-slur-might-be-responsible-for-the-fruits-name.html |website=Slate Magazine |access-date=1 May 2021 |language=en |date=3 July 2014}}</ref> The earliest known reference, under the alternative spelling "caffre" is in the 1888 book ''The Cultivated Oranges, Lemons Etc. of India and Ceylon'' by [[Emanuel Bonavia]], who notes, "The plantation [[coolie]]s also smear it over their feet and legs, to keep off land [[leech]]es; and therefore in Ceylon [Sri Lanka] it has also got the name of ''Kudalu dchi'', or Leech Lime. Europeans call it Caffre Lime."<ref name="Slate 140703"/><ref name="Bonavia">{{cite book |last1=Bonavia |first1=Emanuel |title=The cultivated oranges and lemons, etc. of India and Ceylon, with researches into their origin and the derivation of their names, and other useful information. With an atlas of illustrations |date=1888 |publisher=W. H. Allen & Co |location=London |page=309 |url=https://archive.org/details/cultivatedorange00bonarich/page/309/mode/2up}}</ref> Similarly, H.F. MacMillan's 1910 book ''A Handbook of Tropical Gardening and Planting'' notes, "The 'Kaffir Lime' in Ceylon."<ref name="Slate 140703"/><ref>{{cite book |last1=Macmillan |first1=Hugh Fraser |title=A handbook of tropical gardening and planting with special reference to Ceylon |date=1910 |page=157 |publisher=H. W. Cave & Co. |location=Colombo, Ceylon |url=https://archive.org/details/cu31924001733793/page/n157/mode/2up}}</ref>

Another proposed etymology is directly by Indian Muslims of the imported fruit from the non-Muslim lands to the east to "convey otherness and exotic provenance."<ref name="Slate 140703"/> Claims that the name of the fruit derives directly from the [[South Africa]]n ethnic slur "[[Kaffir (racial term)|kaffir]]" ''(see "South Africa" below)'' are not well supported.<ref name="Slate 140703"/>

''C. hystrix'' is known by various names in its native areas:

* {{lang|jv|jêruk purut}} in [[Javanese language|Javanese]] and {{lang|ms|limau purut}} in [[Malay language|Malay]] (respectively into [[Indonesian language|Indonesian]] and [[Malaysian language|Malaysian]]) both meaning "warty/rough-skinned lime" due to the fruit's bumpy texture.<ref>{{Cite dictionary|url=https://nla.gov.au/nla.obj-60272783/view?partId=nla.obj-436263050#page/n295/mode/1up/search/purut|title=purut|dictionary=A Malay-English dictionary (romanised)|last=Wilkinson|first=Richard James|publisher=Salavopoulos & Kinderlis|location=Mytilene|date=1932|volume=II|page=291|via=TROVE}}</ref><ref>{{Cite web|last=pann|date=2019-04-07|title=Apa itu purut?|url=https://glosarium.org/arti-purut/|access-date=2020-09-02|website=Glosarium Online|language=id-ID}}</ref>
* {{transliteration|zh|jiàn yè chéng}} ({{lang|zh|箭叶橙}} "arrow-leaf lime") in [[Chinese language|Chinese]].
* {{lang|tl|kabuyaw}} or {{lang|tl|kulubot}} in the Philippines.<ref name="CRC Press/Taylor & Francis">{{Cite book|url=https://books.google.com/books?id=IIp-mAEACAAJ|title=CRC World Dictionary of Medicinal and Poisonous Plants: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology. M-Q|date=2012-01-01|publisher=CRC Press/Taylor & Francis|isbn=978-1-4398-9570-2|language=en}}</ref> The city of [[Cabuyao]] in [[Laguna (province)|Laguna]] is named after the fruit.<ref name="CRC Press/Taylor & Francis"/>
*''Kolumichai'', <span lang="ta">கொலுமிச்சை</span> in [[Kongu Tamil]]<ref>{{Cite web|title=Citrus hystrix DC. {{!}} Species|url=https://indiabiodiversity.org/species/show/225573|access-date=2021-12-07|website=India Biodiversity Portal|language=en}}</ref>
* {{transliteration|th|makrud}} or {{transliteration|th|makrut}} ({{lang|th|[[wikt:มะกรูด|มะกรูด]]}}, {{IPA|lang=th|/máʔ.krùːt/}}) in Thailand (a name also used for the [[bergamot orange]]).
* {{transliteration|lo|mak khi hut}} ({{lang|lo|ໝາກຂີ້ຫູດ}}, {{IPA|lang=lo|/ma᷆ːk.kʰi᷆ː.hu᷆ːt/}}) in Laos.
* {{lang|vi|chúc}} or {{lang|vi|chanh Thái}} in [[Vietnam]].<ref name="npark" /><ref>{{cite web |last1=Katzer |first1=Gernot |title=Kaffir Lime (''Citrus hystrix'' DC.) |url=http://gernot-katzers-spice-pages.com/engl/Citr_hys.html |website=Gernot Katzer's Spice Pages |access-date=13 August 2018}}</ref>
*  {{lang|fr|combava}} in [[Réunion]] Island

The [[Citrus micrantha|micrantha]], a similar citrus fruit native to the Philippines that is ancestral to several hybrid limes, such as the [[Key lime]] and [[Persian lime]], may represent the same species as ''C. hystrix'', but the genomic characterization of the kaffir lime has not been performed in sufficient detail to allow a definitive conclusion.<ref>{{cite book |chapter=''Citrus'' taxonomy |last1=Ollitrault |first1=Patrick |last2=Curk |first2=Franck |last3=Krueger |first3=Robert |title=The Citrus Genus |editor-last1=Talon | editor-first1=Manuel | editor-last2=Caruso |editor-first2=Marco | editor-last3=Gmitter |editor-first3=Fred G Jr. |publisher=Elsevier |year=2020 |pages=57–81 |isbn=978-0-12-812163-4 |chapter-url=https://books.google.com/books?id=2wo4swEACAAJ&pg=PA57 |doi=10.1016/B978-0-12-812163-4.00004-8|s2cid=242819146 }}</ref>

===South Africa===
In South Africa, the Arabic ''kafir'' was adopted by White colonialists as "[[Kaffir (racial term)|kaffir]]",<ref name="Slate 140703"/> an ethnic slur for Black Africans.<ref name="straight.com">{{Cite web|date=2014-06-23|first=Veronica |last=Vinje |title=Saying "kaffir lime" is like saying the N-word before "lime"|url=https://www.straight.com/news/671106/veronica-vinje-saying-kaffir-lime-saying-n-word-lime|access-date=2023-02-07|website=The Georgia Straight|language=en}}</ref> Consequently, some authors favour "makrut lime", a less known name. In South Africa, it is usually referred to as "Thai lime".<ref name="McKenna2015">{{citation|first=Maryn|last=McKenna|title=A Food Has a Historic, Objectionable Name. Should We Change It?|date=2014-07-18|url=http://theplate.nationalgeographic.com/2014/07/18/a-food-has-an-historic-objectionable-name-should-we-change-it/|journal=National Geographic|access-date=12 December 2015|archive-date=2015-11-18|archive-url=https://web.archive.org/web/20151118231024/http://theplate.nationalgeographic.com/2014/07/18/a-food-has-an-historic-objectionable-name-should-we-change-it/}}</ref><ref>[http://www.cbc.ca/news/canada/common-lime-name-has-racist-history-1.2698863 Common lime name has racist history] by Khalil Akhtar, CBC News, Jul 8, 2014</ref><ref>{{cite web|url=https://www.ahdictionary.com/word/search.html?id=K5002600|title=Kaf·fir also kaf·fir|work=[[American Heritage Dictionary]]|access-date=18 September 2017}}</ref>

==Description==
''C. hystrix'' is a thorny shrub or small tree, {{convert|6|to|35|ft|0|disp=flip}} tall, with aromatic and [[leaf shape|distinctively shaped "double" leaves]].<ref name="Kumar2008">{{cite book|first=Kuntal|last=Kumar|title=The Original Organics Cookbook: recipes for healthy living|url=https://books.google.com/books?id=eG2zBAAAQBAJ&pg=PT54|date=1 January 2008|publisher=TERI Press|isbn=978-81-7993-155-4|page=54}}</ref><ref name="StaplesKristiansen1999"/> These hourglass-shaped leaves comprise the leaf blade plus a flattened, leaf-like stalk (botanically, a winged [[petiole (botany)|petiole]]). The fruit is rough and green and ripens to yellow; it is distinguished by its bumpy exterior and small size, approximately {{convert|4|cm|0|abbr=on}} wide.<ref name="StaplesKristiansen1999">{{cite book|first1=George|last1=Staples|first2=Michael S.|last2=Kristiansen|title=Ethnic Culinary Herbs: A Guide to Identification and Cultivation in Hawaiʻi|url=https://books.google.com/books?id=jbsdYHEJiDIC&pg=PA27|date=1 January 1999|publisher=University of Hawaii Press|isbn=978-0-8248-2094-7|pages=27–29}}</ref> The fruits have thick skins ([[Fruit_(plant_structure)#Pericarp_layers|pericarps]]) and taste very acidic and slightly bitter.<ref name="Flora Of China">{{cite web |author=jian ye cheng |title=''Citrix hystrix'' in ''Flora of China'' |url=http://efloras.org/florataxon.aspx?flora_id=2&taxon_id=242313263  |access-date=11 February 2023 }}</ref> Flowers can have four to five petals that are white in color and are fragrant.<ref name=":0">{{Cite web |title=Citrus hystrix - Plant Finder |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=291778 |access-date=2024-04-19 |website=www.missouribotanicalgarden.org}}</ref>

==History==
[[Pierre Sonnerat]] (1748–1814) collected specimens of it in 1771–72, and it appears in Lamarck's Encyclopédie Méthodique (1796).<ref>{{cite journal|url=https://www.nparks.gov.sg/sbg/research/publications/gardens-bulletin-singapore/-/media/sbg/gardens-bulletin/4-4-54-2-04-y2002-v54p2-gbs-pg-185.pdf|journal=Gardens' Bulletin Singapore|volume=54|date=2002|pages=185–197|title=Limau Hantu and Limau Purut. the Story of Lime-Leaves (Citrus hystrix DC, Rutaceae)?|author=D. J. MABBERLEY|access-date=12 March 2022}}</ref><ref>{{cite book |last1=Bonavia |first1=Emanuel |title=The cultivated oranges and lemons, etc. of India and Ceylon, with researches into their origin and the derivation of their names, and other useful information. With an atlas of illustrations |date=1888–90 |publisher=W. H. Allen |location=London |page=309 |url=https://archive.org/details/cultivatedorange00bonarich/page/309/mode/2up?q=hystrix |access-date=31 May 2021}}</ref>

Makrut lime appears in texts under the name of kaffir lime in 1868, in Ceylon, where rubbing the juice onto legs and socks prevents leech bites.<ref>{{cite book |last1=Henderson |first1=John (capt. 78th Highlanders.) |editor1-last=Skeet |editor1-first=Ch. J. |title=The History of the Rebellion in Ceylon During Lord Torrington's Government: Affording a Comparison with Jamaica and Governor Eyre |date=1868 |publisher=University of Minnesota |page=58 |access-date=31 May 2021 |url=https://books.google.com/books?id=HAM3AQAAMAAJ&q=%22kaffir+lime%22&pg=PA58}}</ref> This could be a possible origin of the name leech lime.

==Uses==
=== Culinary ===
''C. hystrix'' leaves are used in Southeast Asian cuisines such as [[Indonesian cuisine|Indonesian]], [[Laotian cuisine|Laotian]], [[Cambodian cuisine|Cambodian]], and [[Thai cuisine|Thai]]. The leaves are the most frequently used part of the plant, fresh, dried, or frozen. The leaves are widely used in [[Thai cuisine]]<ref name="thaitravel">{{cite web|last=Loha-unchit|first=Kasma|title=Kaffir Lime –Magrood|url=http://www.thaifoodandtravel.com/ingredients/klime.html|access-date=December 7, 2014}}</ref><ref name="BP-20171112">{{cite news|last1=Sukphisit|first1=Suthon|title=Clean up in kitchen with versatile fruit|url=https://www.bangkokpost.com/lifestyle/social-and-lifestyle/1359143/clean-up-in-kitchen-with-versatile-fruit|access-date=13 November 2017|work=Bangkok Post|date=12 November 2017}}</ref> (for dishes such as [[tom yum]]) and [[Cambodian cuisine]] (for the base paste "[[Kroeung|krueng]]").<ref>{{Cite web|url=https://www.village-bakery.com/kaffir-lime-leaves-substitute/|title=What to Replace Kaffir Lime Leaves With|date=2018-12-17|website=Village Bakery|language=en-US|access-date=2018-12-19}}</ref> The leaves are used in [[Vietnamese cuisine]] to add fragrance to chicken dishes and to decrease the pungent odor when steaming snails. Also, in Vietnamese villages that harvest [[silkworms]], the silkworms in the [[pupa]] stage are [[stir-fried]] with the kaffir lime leaves.<ref>{{cite web |title=How Mountains Of Worm Cocoons Are Turned Into Expensive Silk In Vietnam {{!}} Big Business | website=[[YouTube]] | date=21 August 2022 |url=https://www.youtube.com/watch?v=xBz40ZxKJBs}}</ref> The leaves are used in [[Cuisine of Indonesia|Indonesian cuisine]] (especially [[Balinese cuisine]] and [[Javanese cuisine]]) for foods such as [[soto ayam]] and are used along with [[Syzygium polyanthum|Indonesian bay leaf]] for chicken and fish. They are also found in [[Cuisine of Malaysia|Malaysian]] and [[Cuisine of Myanmar|Burmese]] cuisines.<ref name="hutton">{{cite book|last1=Hutton|first1=Wendy|last2=Cassio|first2=Alberto |url=https://books.google.com/books?id=T-Hh-ezDkVwC&q=kaffir+lime+limau+purut&pg=PA40|title=Handy Pocket Guide to Asian Herbs & Spices|publisher=Periplus Editions|location=Singapore|page=40|isbn=978-0-7946-0190-4|year=2003}}</ref>

The [[Peel (fruit)|rind]] (peel) is commonly used in Lao and [[Thai curry]] paste, adding an aromatic, astringent flavor.<ref name=thaitravel /> The [[Zest (ingredient)|zest]] of the fruit, referred to as combava,<ref>{{Cite journal | last1=Aubert  | first1=B. | last2=Bove | first2=C. | year=1984| url=https://iocv.ucr.edu/sites/default/files/2020-06/9th057_061.pdf | title=Mild and Severe Strains of Citrus Tristeza Virus in Reunion Island | journal=Ninth International Organization of Citrus Virology Conference}}</ref> is used in [[creole cuisine]] to impart flavor in [[Flavored liquor|infused rums]] and [[rougails]] in [[Mauritius]], [[Réunion]], and [[Madagascar]].<ref>{{Cite news | url=https://economictimes.indiatimes.com/industry/cons-products/liquor/mauritian-rum-has-a-distinct-character-to-it-sweeter-and-smoother/articleshow/46647281.cms | title=Mauritian rum has a distinct character to it: Sweeter and smoother| newspaper=The Economic Times| date=2015-03-22}}</ref> In Cambodia, the entire fruit is [[candied fruit|crystallized or candied]] for eating.<ref name=dyphon>Dy Phon Pauline, 2000, ''Plants Used In Cambodia'', printed by Imprimerie Olympic, Phnom Penh</ref>

===Medicinal===
The juice and rinds of the peel are used in traditional medicine in some Asian countries; the fruit's juice is often used in shampoo and is believed to kill head lice.<ref name="StaplesKristiansen1999"/>

===Other uses===
The juice is used as a cleanser for clothing and hair in Thailand<ref name="BP-20171112"/> and occasionally in Cambodia. [[Lustral water]] mixed with slices of the fruit is used in religious ceremonies in Cambodia.

Makrut lime oil is used as raw material in many fields, including pharmaceutical, agronomic, food, sanitary, cosmetic, and perfume industries. It is also used extensively in aromatherapy and as an essential ingredient in various cosmetic and beauty products.<ref>{{Cite journal|url=https://onlinelibrary.wiley.com/doi/epdf/10.1002/ffj.3626|doi=10.1002/ffj.3626|title=Techniques for essential oil extraction from makrut lime and its application in health care products—A review|year=2021|last1=Suresh|first1=Anuja|last2=Velusamy|first2=Sangeetha|last3=Ayyasamy|first3=Sudha|last4=Rathinasamy|first4=Menaha|journal=Flavour and Fragrance Journal|volume=36|pages=5–21|s2cid=226314486|url-access=subscription}}</ref>

<gallery>
File:Fish stuffed with Thai herbs.jpg|[[Channa striata|Striped snakehead]] fish stuffed with ''C. hystrix'' and [[Cymbopogon|lemongrass]] in preparation for steaming
File:Flickr - cyclonebill - Tom yam.jpg|''C. hystrix'' leaves floating in [[tom yum]]
File:Citrus hystrix DC. (AM AK305877-3).jpg|Fruit longitudinal section
File:Combava Rind Madagascar.jpg|Dried fruit rinds
File:Combava Powder Madagascar.jpg|Powdered fruit rind, used in [[Malagasy cuisine]]
File:Phanaeng kai.jpg|Cut leaf strips on chicken [[phanaeng]]
File:2022.08-516-248ap1 Large bags with Citrus hystrix leaves for sale in Phou Puy Wholesale Vegetable Market in Battambang, Cambodia sat27aug2022-1516h.jpg|''C. hystrix'' leaves for sale in Phou Puy Wholesale Vegetable Market in [[Battambang]], Cambodia (August 2022)
</gallery>

==Cultivation==
[[File:Kaffir Lime (Citrus hystrix) 1.jpg|thumb|Small ''C. hystrix'' shrub in pot]]
''C. hystrix'' is grown worldwide in suitable climates as a garden shrub for home fruit production. It is well suited to [[container garden]]s and for large [[flower pot|garden pots]] on [[patio]]s, [[Terrace (building)|terraces]], and in conservatories.

==Main constituents==
The compound responsible for the characteristic aroma was identified as [[citronellal|(–)-(''S'')-citronellal]], which is contained in the leaf oil up to 80 percent; minor components include [[citronellol]] (10 percent), [[nerol]] and [[limonene]].

From a stereochemical point of view, it is remarkable that makrut lime leaves contain only the (''S'') [[stereoisomer]] of citronellal, whereas its [[enantiomer]], (+)-(''R'')-citronellal is found in both [[lemon balm]] and (to a lesser degree) [[lemon grass]], (however, citronellal is only a trace component in the latter's essential oil).

Makrut lime fruit peel contains an essential oil comparable to lime fruit peel oil; its main components are limonene and [[pinene|β-pinene]].<ref name=Ng/><ref name="kasuan">{{cite journal|last=Kasuan|first=Nurhani|url=http://www.ukm.my/mjas/v17_n3/Nurhani.pdf|journal=Malaysian Journal of Analytical Sciences|title=Extraction of ''Citrus hystrix'' D.C. (Kaffir Lime) Essential Oil Using Automated Steam Distillation Process: Analysis of Volatile Compounds|volume=17|issue=3|pages=359–369|year=2013}}</ref>

==Toxicity==
''C. hystrix'' contains significant quantities of [[furanocoumarins]], in both the peel and the pulp.<ref name="Dugrand-Judek et al. 2015">{{cite journal |last1=Dugrand-Judek |first1=Audray |last2=Olry |first2=Alexandre |last3=Hehn |first3=Alain |last4=Costantino |first4=Gilles |last5=Ollitrault |first5=Patrick |last6=Froelicher |first6=Yann |last7=Bourgaud |first7=Frédéric |title=The Distribution of Coumarins and Furanocoumarins in ''Citrus'' Species Closely Matches ''Citrus'' Phylogeny and Reflects the Organization of Biosynthetic Pathways |journal=PLOS ONE |date=November 2015 |volume=10 |issue=11 |article-number=e0142757 |doi=10.1371/journal.pone.0142757 |pmid=26558757 |pmc=4641707|bibcode=2015PLoSO..1042757D |doi-access=free }}</ref> Furanocoumarins are known to cause [[phytophotodermatitis]],<ref name="McGovern and Barkley 2000">{{cite journal |journal=The Electronic Textbook of Dermatology |url=http://telemedicine.org/botanica/bot1.htm |title=Botanical Dermatology |last1=McGovern |first1=Thomas W. |last2=Barkley |first2=Theodore M. |at=Section&nbsp;[http://telemedicine.org/botanica/bot5.htm Phytophotodermatitis] |publisher=Internet Dermatology Society |date=2000 |volume=37 |issue=5 |doi=10.1046/j.1365-4362.1998.00385.x |pmid=9620476 |s2cid=221810453 |access-date=November 29, 2018}}</ref> a potentially severe skin inflammation. Cases of phytophotodermatitis induced by external use of ''C.&nbsp;hystrix'' have been reported.<ref name="Koh and Ong 1999">{{cite journal |last1=Koh |first1=D. |last2=Ong |first2=C. N. |title=Phytophotodermatitis due to the application of ''Citrus hystrix'' as a folk remedy |journal=Br J Dermatol |date=April 1999 |volume=140 |issue=4 |pages=737–738 |pmid=10233333 |doi=10.1046/j.1365-2133.1999.02782.x|s2cid=45603195 }}</ref>

==See also==
{{Commons category|Citrus hystrix}}
*{{annotated link|Citrus taxonomy}}

==References==
{{Reflist|30em}}

{{Citrus}}
{{Taxonbar|from=Q465934}}

[[Category:Southeast Asian cuisine]]
[[Category:Limes (fruit)]]
[[Category:Citrus]]
[[Category:Flora of China]]
[[Category:Flora of tropical Asia]]
[[Category:Fruits originating in Asia]]
[[Category:Garden plants of Asia]]
[[Category:Herbs]]
[[Category:Lao cuisine]]
[[Category:Filipino cuisine]]
[[Category:Spices]]
[[Category:Thai cuisine]]
[[Category:Austronesian agriculture]]