Кумкват: описание, виды и свойства

Species of small fruit bearing tree

Kumquats ('/k//ʌ//m//k//w//ɒ//t/ KUMkwot), or cumquats in Australian English, are a group of small, angiosperm, fruit bearing trees in the family Rutaceae. Their taxonomy is disputed. They were previously classified as forming the now historical genus Fortunella or placed within Citrus, sensu lato. Different classifications have alternatively assigned them to anywhere from a single species, Citrus japonica, to numerous species representing each cultivar. Recent genomic analysis defines three pure species, Citrus hindsii, C. margarita and C. crassifolia, with C. × japonica being a hybrid of the last two. The edible fruit closely resembles the orange (Citrus sinensis) in color, texture, and anatomy, but is much smaller, being approximately the size of a large olive. The kumquat is a fairly cold hardy citrus.

The English word kumquat is a borrowing of the Cantonese (; ), from "golden" + "orange".

Kumquat plants have thornless branches and extremely glossy leaves. They bear dainty white flowers that occur in clusters or individually inside the leaf axils. The plants can reach a height from , with dense branches, sometimes bearing small thorns. They bear yellowish orange fruits that are oval or round in shape. The fruits can be in diameter and have a sweet, pulpy skin and slightly acidic inner pulp. The fruit is often eaten whole by humans and has a taste which is sweet and somewhat sour. Kumquat trees are self pollinating.

The kumquat plant is native to Southern China. The historical reference to kumquats appears in literature of China from at least the 12th century. and are now found across the world. (confirmed 2017).

Kumquats do not grow well from seeds and so are vegetatively propagated by using rootstock of another citrus fruit, air layering, or cuttings. The Centennial Variegated is another cultivar of the Nagami kumquat. It originated from the open pollination of a Nagami kumquat tree. The fruits are striped light green and yellow when underripe, and turn orange and lose their stripes when they ripen. They are oval shaped, necked, 2.5 inches long and have a smooth rind. They mature in winter. This cultivar arose spontaneously from the oval kumquat (Citrus margarita). It produces a greater proportion of fruit to peel than the oval kumquat, and the fruit are rounder and sometimes necked. Fruit are distinguishable by their variegation in color, exhibiting bright green and yellow stripes,

A raw kumquat is 81% water, 16% carbohydrates, 2% protein, and 1% fat (table). In a reference amount of , raw kumquat supplies 71 calories and is a rich source of vitamin C (53% of the Daily Value), with no other micronutrients in significant content (table).

The essential oil of the kumquat peel contains much of the aroma of the fruit, and is composed principally of limonene, which makes up around 93% of the total. Besides limonene and alpha pinene (0.34%), both of which are considered monoterpenes, the oil is unusually rich (0.38% total) in sesquiterpenes such as α bergamotene (0.021%), caryophyllene (0.18%), α humulene (0.07%) and α muurolene (0.06%), and these contribute to the spicy and woody flavor of the fruit. Carbonyl compounds make up much of the remainder, and these are responsible for much of the distinctive flavor. These compounds include esters such as isopropyl propanoate (1.8%) and terpinyl acetate (1.26%); ketones such as carvone (0.175%); and a range of aldehydes such as citronellal (0.6%) and 2 methylundecanal. Other oxygenated compounds include nerol (0.22%) and Trans lialool oxide (0.15%).