The kiwifruit is also known by its short name, kiwi, in some parts of the world as well as Chinese gooseberry, and Yang Tao. Interior of the fruit is dazzling green flesh with radiating lighter green spikes. Scattered between the spikes are the miniature edible dark purple to almost black seeds. The flesh is soft and juicy with a creamy texture and sweet/tart (at times acidic) flavour. Exterior is a brown coloured skin covered by short, stiff, dense hairs.
Actinidia deliciosa (kiwi) is actually a berry capable of growing anywhere citrus fruits can grow. The plant is able to lie dormant in sub-zero temperatures, after which it flourishes and produces flowers of cream colour roughly one to two inches in size. Both male and female flowers have to be present for the female to be able to produce the fruit. However, one male plant is able to pollinate many female plants. The pollination in carried out by the typical garden animals like honey bees and butterflies, or even the wind.
History of Kiwifruit
Originating in the Yangtze Valley of northern China, the kiwifruit is known to have been cultivated for at least three hundred years. The Chinese never showed much interest in exploiting the fruit, nor expanding its local cultivation initially. It was grown in an area of dense population and growth was restricted.
In 1900 seeds made their way into England, where the plants bloomed and flourished by 1909. While fruits were produced where male and female plants existed side by side, for the most parts only solitary vines were planted for ornamental purposes. At about this time, seeds were also introduced to New Zealand with the vines producing fruit by 1910. By the 1930s different people were propagating the plants. As production grew so did the marketing and the fruit became very popular with the American servicemen based in New Zealand in World War II. By 1953 commercial export to Japan, North America and Europe and to a lesser degree to Australia, U.K and Scandinavia started. In 1962 the increasing demand, and to further increase its market appeal, the name of the fruit was officially changed from Chinese gooseberry to kiwifruit. This name was chosen as a tribute to the native New Zealand kiwi bird whose physical characteristics of fuzzy brown coat are similar to kiwifruit’s skin. New Zealand was responsible for supplying 99% of kiwifruit’s global requirement.
From New Zealand the plants and seeds ended up in the U.S.A. with special nurseries taking root in 1966. The Fruit and Fruit Technology Research Institute of Stellenbosch, South Africa also started experimental plantings in different places in the country. The vines grew with success in north-eastern Transvaal. The fruit was already being cultivated in Cambodia, Vietnam, Laos, France, Spain, Belgium and Italy. With lower returns from apple growing, French interest was rejuvenated in kiwi production in 1971. Greece stepped up production for export to Europe to cover the seasonal gap when New Zealand fruit was not available. Currently, Italy, New Zealand, Chile, France, Japan and the United States are the world's top producers of kiwis.
Health Benefits of Kiwifruit
While the Chinese have never favoured the fruit, even they have used it as a tonic for children during the growing years and women after child birth. Recent popularity of the fruit has only intensified the research into its beneficial properties and according to the University of Innsbruck, Austria, consuming a fruit that is ripe to the point of spoiling only enhances the beneficial aspects of the fruit.
Kiwis contain a naturally high quantity of antioxidants and other phytochemicals that help to enhance the immune system function by fighting off stress, inflammation and bacterial and viral attacks. The high fibre content adds roughage and the proteolytic enzyme actinidin facilitates the digestion of proteins for smooth flow of food through the digestive tract at an even pace. The polysaccharides in Kiwis prevent the bonding of enteropathogens and trigger the probiotic bacteria in the colon into action. The steady movement of food through the digestive tract also regulates blood sugar absorption which eliminates undesirable sugar spikes and troughs, making it an ideal fruit for diabetics. Furthermore, consuming a diet high in fibre is believed to lower cholesterol levels which in turn protects against heart disease.
The elevated vitamin C content in the fruit rids the body of free radicals known to damage healthy cells. This helps to cut down on the inflammation in bone and connective tissues and alleviating symptoms of rheumatoid arthritis or osteoarthritis. Elimination of free radicals is also associated with protection against various cancers like lung, colon, mouth, and stomach. Kiwifruit is cytotoxic to malignant cancer cells and does not harm the healthy cells. Catechin, a phytochemical found in kiwi reduces the toxicity and stimulates bone marrow production. Vitamin C is also associated with lowering blood pressure by properly dilating blood vessels and preventing problems like atherosclerosis, cholesterol and cardiovascular disease. It is also believed to reduce the triglycerides in the blood, thus helping to prevent blood clots. Kiwi fruit has more vitamin C than oranges and benefits the respiratory system against ailments like asthma, cough and shortness of breath.
The phytochemicals lutein and zeaxanthin found in kiwi benefit eye health. These components are essential to the human eye along with vitamin A and protect against age-linked macular degeneration, cataracts and other vision disorders. The folate in kiwis is essential for protecting the unborn baby from neural tube defects and contributes to the overall health of the developing foetus.
Kiwis are natural anti-aging agents. The vitamin E in kiwi helps to eliminate the fine lines thus reducing wrinkles, in addition to minimizing the effects of ultra-violet radiation on the skin. The vitamin C keeps the skin firm and speeds up the process of healing in case of cuts and abrasions. Kiwis also aids in collagen synthesis which keeps the skin smooth and retain it natural elasticity leading to younger looking skin.
Nutritional Value of Kiwifruit
Kiwifruit is rich in nutrients but low in calories. One cup of sliced kiwifruit supplies 5 grams (16 % of the U.S Recommended Daily Allowance) of fibre to help keep your digestive system in top shape. It supplies both soluble fibre that plays a protective role in heart disease and insoluble fibre responsible for averting problems like constipation, and haemorrhoids.
There are few other foods that provide equivalent amounts of folic acid as kiwi. Folate is such an essential vitamin that several countries are thinking of adding it to bread or flour to make certain that the population gets sufficient quantities. While bananas are often thought of as a good source of potassium, kiwifruit supplies roughly the same amount without the calories. Kiwi is the perfect low sodium way to get sufficient quantities of potassium. One serving of kiwi has 20% more potassium than a banana. Oranges have a long established reputation of being a good source of vitamin C, but kiwis have even more. One serving provides roughly 230% of the U.S Recommended Daily Allowance. It also supplies 10% of the RDA of vitamin E, which is twice as much as that of an avocado.
Kiwi is ranked higher than all other fruits and veggies, except yellow corn for lutein. It also supplies 5.5% of the RDA of calcium, 4% iron, 6% magnesium and 8% copper. It provides trace amounts of manganese required by enzymes in protein metabolism and food energy, and chromium, a key element in regulation of heartbeat and carbohydrate metabolism.
Uses of Kiwifruit
Kiwifruit’s characteristic looks and rejuvenating taste make them great to eat fresh. They can easily be peeled with a paring knife and enjoyed sliced or they may be cut in half and the flesh scooped out with a spoon. The skin too is edible like that of a pear and only enhances the nutrients and fibre of the fruit. The fuzzy hairs can be easily rubbed off before consumption. Kiwi should be eaten soon after cutting as the enzymes actinic and bromic acids have food tenderizing properties and tend to tenderize the fruit itself.
Kiwi can be served as an appetizer, in salads, fowl, meat dishes, salads, pies, puddings, cake-fillings and with ice-cream, breads and as a variety of beverages. When serving in salads it is best to put kiwi in at the last moment so it doesn’t make the salad soggy. Likewise it is best not to use kiwifruit with yogurt and gelatin-based products because the enzymes present in it break down the proteins in these foods. If it has to be used with these products, then cook the fruit for a few minutes to neutralize the enzymes. These very same properties make kiwi a great meat tenderizer. Simply rub the meat with the kiwi flesh, or place slices of kiwifruit on the meat. Remove or scrape off the fruit after about ten minutes or the enzymatic action can be extreme. For best results, cook the meat immediately.
The over ripe fruits are used as flavours in ice cream and for commercial production of juice. It is typically blended with apples to minimize the acidity. The under-ripe fruits are selected for turning into jelly, jam and chutney. Freeze dried fruits are sold in health food outlets in Sweden and Japan. In Japan they are even sold coated with chocolate. Whole fruits are also good to pickle with vinegar, brown sugar and spices.
Numerous clinical trials investigating various health benefits of kiwifruit are being investigated in different laboratories. The vitamin C in kiwi is linked to protection against asthma. One study published in April 2004 issue of Thorax found children consuming more kiwifruit had 44% fewer incidences of wheezing.
According to another study, the serotonin in kiwifruit aids in sleeping better. Consumption of the fruit helped with total sleep time and efficiency. The flavonoids quercitin, catechin, rutin, naringenin and epicatechin modulate sleep generating receptors, working as a sedative. Kiwi peel is a powerful ingredient for developing natural sleeping aids.
Another astounding benefit of kiwifruit is its capability to accommodate absorption of iron by the body. The phytochemicals lutein and zeaxanthin found in kiwi improve the presence of iron in the body and prevent iron deficiency ailments. In another study it was shown that kiwi helps to regulate adipogenesis, which is vital in diabetes prevention.