Wednesday, January 16, 2008

Natural Health Fruit: Kiwi

The kiwifruit is the cooked fruit of a cultivar group of the woody vine Actinidia deliciosa and hybrids between this and other species in the genus Actinidia. The fruit was developed in New Zealand. The Actinidia is inhabitant to southern China. The most common cultivars of kiwifruit are elliptical, about the size of a large hen's egg (5–8 cm / 2–3 in long and 4.5–5.5 cm / 1¾–2 in diameter). It has a gristly, dull green-brown skin and dazzling green or golden flesh with rows of small, black, edible seeds. The fruit has a pliable texture and a unique flavour.

In North America, South America, Europe, and East Asia most community refer to the fruit basically as "kiwi." Initially known as the Chinese Gooseberry, the natural health fruit was renamed for marketing reasons in the mid-20th century, first to melonette, and then to kiwifruit. The final name was selected for the aboriginal New Zealand bird, kiwi, which is one of the country's national symbols. The second renaming was done in order to evade a tariff on imported melons.

The familiar cultivar Actinidia deliciosa 'Hayward' was developed by Hayward Wright in Avondale, New Zealand about 1924. It was initially grown in domestic precincts, but commercial planting started in the 1940s. Italy is now the foremost 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 completed it to the top 10 list of kiwifruit producing countries. In China, this natural health fruit is grown mainly in the precipitous area upstream of the Yangtze River. It is also grown in other areas of China, including Sichuan.

New Zealand exported the fruit to the US in the 1950s. In the middle of the exporters was the prominent make company Turners and Growers, who were calling the berries melonettes, because the name Chinese gooseberry had political connotations due to the Cold War. An American importer, Norman Sondag of San Francisco, complained that melonettes was as bad as Chinese gooseberry because melons and berries were both subject to high import tariffs. In June 1959, during a convention of Turners and Growers management in Auckland, Jack Turner suggested the name kiwifruit which was adopted and later became the industry-wide name.

Fruit Values

Kiwifruit is a wealthy source of vitamin C, 1.5 times the DRI scale in the US. Its potassium content by weight is slightly less than that of a banana. It also restrains vitamins A and E. The skin is a high-quality source of flavonoid antioxidants. The kiwifruit seed oil contains on average 62% alpha-linolenic acid, an omega-3 fatty acid. Kiwifruit is often reported to have mild laxative effects, possibly because of the high level of dietary fibre.

Raw kiwifruit is also rich in the protein-dissolving enzyme actinidin, (in the same family of thiol proteases as papain), which is commercially valuable as a meat tenderizer but can be an allergen for some individuals. Particularly, people allergic to latex, papayas or pineapples are likely to be allergic to kiwifruit also. Reactions include tingling and sore mouth; swelling of the lips, tongue and face; rash; vomiting and abdominal pain; and, in the most severe cases, breathing difficulties, wheezing and collapse. The most common symptoms were unlikable itching and soreness of the mouth, with the most common severe symptom being wheezing. Rigorous symptoms were most likely to occur in young children.

This enzyme makes raw kiwifruit inappropriate for use in desserts containing milk or any other dairy products which are not going to be served within hours, because it soon starts to digest milk proteins. This 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, the U.S. Department of Agriculture advises that cooking the fruit for a few minutes before adding it to the gelatin will overcome this effect. Pieces kiwifruit has long been repeatedly used as a garnish atop beated cream on one of New Zealand and Australia's favourite desserts, the pavlova.


1 comment:

Drug Natural said...

I did not know that Kiwi had so many beneficial qualities. I also did not know it had Omega-3 Fatty Acids. I'll have to add it to the list of Omega-3 foods.