Citrus hystrix, commonly known in English as kaffir lime, is a fruit native to Indochinese and Malesian ecoregions in India, Philippines, Bangladesh, Indonesia, Malaysia and Thailand, and adjacent countries. It is used in Southeast Asian cuisine.
Citrus hystrix is a thorny bush, 5-10m tall, with aromatic and distinctively shaped “double” leaves. The kaffir lime is a rough, bumpy green fruit. The green lime fruit is distinguished by its bumpy exterior and its small size (approx. 4?cm wide).
Citrus hystrix Kabuyao(Cabuyao) fruit (left), used in Southeast Asian cooking, with galangal root.
Kaffir lime leaves are used in some South East Asian cuisines such as Indonesian, Lao, Cambodian, and Thailand.
The rind of the kaffir lime is commonly used in Lao and Thai curry paste, adding an aromatic, astringent flavor. The zest of the fruit is used in creole cuisine to impart flavor in “arranged” rums in the Martinique, R?union island and Madagascar. However, it is the hourglass-shaped leaves (comprising the leaf blade plus a flattened, leaf-like leaf-stalk or petiole) that are used most often in cooking. They can be used fresh or dried, and can be stored frozen. The leaves are widely used in Thaiand Lao cuisine (for dishes such as tom yum), and Cambodian cuisine (for the base paste “Krueng”). Kaffir lime leaves are used in Vietnamese cuisine with chicken to add fragrance. They are also used when steaming snails to decrease the pungent odor while cooking. The leaves are also used in Indonesian cuisine (especially Balinese cuisine and Javanese cuisine), for foods such as sayur asam, and are used along with Indonesian bay leaf for chicken and fish. They are also found in Malaysian and Burmese cuisines. The juice is generally regarded as too acidic to use in food preparation. In Cambodia, the entire fruit is crystallized/candied for eating.
The juice and rinds are used in traditional Indonesian medicine; for this reason the fruit is referred to in Indonesia as jeruk obat (“medicine citrus”). The oil from the rind has strong insecticidal properties.
The juice finds use as a cleanser for clothing and hair in Thailand and very occasionally in Cambodia. Lustral water mixed with slices of the fruit is used in religious ceremonies in Cambodia. MaxRoot gel is made of kaffir lime extract and has been used since old age in the northern parts of Thailand in a particular and secret way of preparation to maintain health and beauty of the Siam people?s shiny hair.
Citrus hystrix is grown worldwide in suitable climates as a garden shrub for home fruit production. It is well suited to container gardens and for large garden pots on patios, terraces, and in conservatories.
The compound responsible for the characteristic aroma was identified as (?)-(S)-citronellal, which is contained in the leaf oil up to 80%; minor components include citronellol (10%), nerol and limonene.
From a stereochemical point of view, it is remarkable that kaffir 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, (note, however, that citronellal is only a trace component in the latter’s essential oil).
Kaffir lime fruit peel contains an essential oil comparable to lime fruit peel oil; its main components are limonene and ?-pinene.