Kiwifruit
The
kiwifruit is the edible
fruit of a
cultivar group of the
woody vine Actinidia deliciosa and
hybrids between this and other species in the genus
Actinidia. It is marketed worldwide as kiwifruit but is more commonly called
kiwi in North and South America and in Europe. It is sometimes considered the national fruit of
New Zealand.
The most common
cultivars of kiwifruit are oval, and about the size of a large hen's egg (5-8 cm long and 4.5-5.5 cm diameter). It has a hairy, dull green-brown skin that most people peel off before consumption. The flesh is bright green or golden with rows of small, black, edible seeds. The texture of the fruit is soft and the flavour is sometimes described as a mix of
strawberry,
banana, and
pineapple.
The fruit gets its name from a marketing strategy, naming it after the
kiwi, the
national bird of
New Zealand, where the fruit was first commercially popularised in
1959 by the New Zealand fruit-and-vegetable export company
Turners and Growers; previously it was known as the
Chinese gooseberry, but due to the
Cold War, the
Chinese label seemed unfit for popularization of the fruit in Western countries. Growers gradually adopted the name and in
1974 the kiwifruit became the official trade name.
In
North America,
South America and
Europe, the "fruit" part of the name is usually dropped, and most people associate "kiwi" with the fruit rather than the bird. This usage can cause some minor confusion and tends to annoy or offend many New Zealanders. To minimize confusion about what a "kiwi" is—a bird, a fruit or a New Zealander—most New Zealand Kiwifruit is now marketed under the brand-name label
Zespri which is trademarked by a marketing company domiciled in New Zealand, ZESPRI International. The branding move also served to distinguish New Zealand kiwifruit from fruit produced by other countries who could cash in on the "Kiwi" name, as it was not trademarked.
Actinidia deliciosa is native to southern
China, where it is declared as the
National fruit of
China. Other species of
Actinidia are also found in China and range east to
Japan and north into southeastern
Siberia. Cultivation spread from China in the early
20th century, when seeds were introduced to New Zealand by
Isabel Fraser, the principal of Wanganui Girls' College, who had been visiting mission schools in China. The seeds were planted in
1906 by a
Wanganui nurseryman,
Alexander Allison, with the vines first fruiting in
1910. People who tasted the fruit then thought it had a
gooseberry flavour and began to call it the
Chinese Gooseberry, but being from the actinidia family it is not related to the
Grossulariaceae (gooseberry) family.
The familiar cultivar
Actinidia deliciosa 'Hayward' was developed by Hayward Wright in
Avondale, New Zealand around
1924. It was initially grown in domestic gardens, but commercial planting began in the
1940s. Italy is now the leading producer of kiwifruit in the world, followed by New Zealand, Chile, France, Greece, Japan and the United States. Kiwifruit is still produced in its birthplace China, but China has never made it to the top 10 list of kiwifruit producing countries. In China, it is grown mainly in the mountainous area upstream of the
Yangtze River. It is also grown in other areas of China, including
Sichuan.
Names
This fruit is native to China and had a long history before it was commercialized as kiwifruit.Hence it has many other older names especially in the Chinese language.In
Chinese:
*
Macaque peach (獼猴桃
míhóu táo): the most common name
* Unusual fruit or wonder fruit (奇異果
qíyì gu'): the most common name in
Taiwan and
Hong Kong (奇異果
kay yee goh). A quasi-transliteration of "kiwifruit", literally "strange fruit".
* Willow peach (楊桃
yáng táo - note that this term also refers to the
Carambola)
* Goat peach (羊桃
yáng táo); these two are homophonous with
poplar peach (楊桃), meaning
carambola.
* Hairy pear (毛梨
máo lí)
* Vine pear (藤梨
téng lí)
Almost all kiwifruit in commerce belong to a few cultivars of
Actinidia deliciosa: 'Hayward', 'Chico', and 'Saanichton 12'. The fruit of these cultivars are practically indistinguishable from each other and match the description of a standard kiwifruit given at the head of this article.
A new Cultivar Group of
Actinidia chinensis known as Golden Kiwifruit or "Chinabelle", with yellow flesh and sweeter, less acidic flavour resembling a tropical
fruit salad, was produced by the New Zealand
Crown Research Institute,
HortResearch and is being marketed worldwide in increasing volumes. Some wild vines in China have yellow fruit but are small and not commercially viable. Seeds from these plants were imported to New Zealand in 1987 and the company took eleven years to develop the new fruit through cross-pollination and grafting with green kiwi vines. Golden Kiwifruit have a smooth, bronze skin, a pointed cap at one end and distinctive golden yellow flesh with a less tart and more tropical flavour than green kiwifruit. It has a higher market price than green kiwifruit. Unlike the green cultivars, it is less hairy, so it can be eaten whole after rubbing off the thin, fluffy coat.
Kiwifruit is a rich source of
vitamin C. Its
potassium content by weight is slightly less than that of a banana. It also contains
vitamins A and
E, The skin is a good source of
flavonoid antioxidants.
Raw kiwifruit is also rich in the protein-dissolving enzyme actinidin, (in the same family of
thiol proteases as
papain), which is commercially useful as a meat tenderizer but can be an
allergen for some individuals. Specifically, people allergic to
papayas or
pineapples are likely to be allergic to kiwifruit also.
This enzyme makes raw kiwifruit unsuitable for use in desserts containing
milk or any other
dairy products which are not going to be served within hours, because it soon begins to dissolve milk proteins. This also applies to gelatin based desserts, as well, as the actinidin will dissolve the collagen proteins in gelatin very quickly, either liquifying the dessert, or preventing it from solidifying. However, sliced kiwifruit has long been regularly used as a garnish atop whipped cream on one of
New Zealanders' favourite desserts, the
pavlova.
 |
Kiwi Fruit orchard, The North Island, New Zealand |
Kiwifruit can be grown in most temperate climates with adequate summer heat. Where
Actinidia deliciosa is not hardy, other species can be grown as substitutes.
Kiwifruit is commercially grown on sturdy support structures, as it can produce several tonnes per hectare, more than the rather weak vines can support. These are generally equipped with a watering system for irrigation and frost protection in the spring.
Kiwifruit vines require vigorous pruning, similar to that of grapevines. Fruit is borne on one-year-old and older canes, but production declines as each cane ages. Canes should be pruned off and replaced after their third year.
Kiwifruit plants are normally
dioecious, meaning that individual plants are male or female. Only female plants bear fruit, and only when pollenized by a male plant. One male
pollenizer is required for each three to eight female vines. An exception is the cultivar 'Issai', a hybrid (
Actinidia arguta x rufa) from Japan, which produces perfect flowers and can self-pollinate; unfortunately it lacks vigour, is less hardy than most
A. arguta forms and is not a large producer.
Kiwifruit is notoriously difficult to
pollinate because the flowers are not very attractive to bees. Some producers blow collected pollen over the female flowers. But generally the most successful approach is
saturation pollination, where the bee populations are made so large (by placing hives in the orchards) that bees are forced to use this flower because of intense competition for all flowers within flight distance.
|
One way to eat a kiwifruit. |
Kiwifruit can be eaten whole (including the skin), like an apple; cut in half and eaten, like a
passion fruit or peeled and sliced, like a pineapple. For people who prefer not to eat the skin, cut the fruit in half and then scoop the flesh out with a spoon. Another method would be to slice the fruit into several coins about .25" thick, possibly cutting each coin into quarters, and serving it, skin-on, as a platter or with plain yogurt.
Peeling hint: peel using a potato peeler, drawing it up from the bottom towards the thicker, harder end where it was attached to its branch. Cutting thus 'against the grain' releases juice which lubricates the blade and a swifter, cleaner cut results.
Kiwifruit has an acid juice containing
proteases, making it ideal as a meat tenderiser when roasting. In
New Zealand and
Australia, kiwifruit are a favourite topping for
pavlova, although the proteases break down the cream, meaning the pavlova must be consumed promptly.
*
List of fruits*
Zespri International Limited*
Purdue University NewCROP*
NCBI's taxonomy browser *
Photos of kiwifruit and alfalfa pollination in California
