Ingredient of the Month - Kiwi Fruit
The Kiwi fruit plant belongs to the family Actinidia. Although there are around 400 varieties, the ones most widely grown for commercial fruiting purposes are deliciosa. When ripe the flesh is soft with rows of tiny black seeds, which are also edible. The flavour can be described as a cross between strawberries, bananas and pineapple and the fruit can be eaten raw or cooked. Kiwi fruit is high in antioxidant vitamin C and a good source of fibre, vitamin E and potassium. It also contains folate, copper, vitamin E and lutein.
Origin and History
The Kiwi fruit is indigenous to southeast Asia. The vines can be found growing wild on the edges of forests near to China's Yangtze Valley, and reach heights of 30 feet or more, and the fruit has been known to the inhabitants of China since ancient times.
The West was introduced to this fruit relatively late on in history and it wasn't until the 19th century that samples of both the fruit and seeds were sent to England and in 1905 plant cuttings were taken to the United States and seeds sent to New Zealand where the fruit was renamed the "Chinese Gooseberry" where the fruit started to be produced commercially in 1940. By the early 1960s New Zealand was exporting crops to the United States where it was re-named Kiwi fruit after New Zealand's national bird the "kiwi."
By the 1970s it was commercially grown in California and available for the first time in supermarkets throughout the country. It was also about this time that nouvelle cuisine started taking it's hold worldwide at which point the Kiwi fruit gained great popularity as the "darling" of the new eating craze, especially as a garnish.
Today Kiwi fruit is available worldwide and is commercially grown is several countries including Australia, Chile, France, Greece, Japan, New Zealand, Spain and the USA.
Cultivation and Processing
Kiwi fruit can be grown in most temperate climates so long as adequate summer heat occurs. Commercially grown vines generally crop in the fourth season with full production being reached in 8 to 12 years. Dormant plants obtained from a nursery can be planted out during the spring after the danger of frost and should be planted to the same depth as the plants grew in the nursery. After planting, prune the plant back to one single, healthy shoot 6 to 12 inches long. Kiwi fruit plants are normally male or female.
The female plants bear the fruit but a male plant is necessary in order for pollination to take place. In general you need one male plant for three to eight females. Although it is now possible to get self pollinators, their vigour is generally inferior, producing much fewer fruit.
The vines are trained on sturdy supports or trellises which not only enables the plants to get plenty of light and good air circulation but also allows heavier cropping as, unsupported, the vines aren't that strong and would probably be wind damaged.
Buying and Storing
It is best to buy firm Kiwi fruit and allow them to ripen at home. A Kiwi fruit is ripe when plump and slightly soft to the touch with a fragrant smell. Choose Kiwi fruit with no bruises or soft spots and avoid fruit with wrinkles or signs of exterior damage.
Store unripe fruit at room temperature until the skin indents slightly when touched. It normally takes 3 to 5 days to ripen Kiwis at room temperature although to can hasten ripening by placing the fruit in a paper bag with an apple or banana. Ripe Kiwis can be kept in the refrigerator for up to three weeks. Place them in a plastic bag to help reduce moisture loss.
Freezing Kiwi fruit doesn't impair either the flavour or colour and is therefore an excellent idea when you have lots of fruit available. Also it does NOT inactivate the enzymes which break down protein. They can be frozen whole, sliced or crushed. Choose fully ripe fruit. Sliced fruit freezes and thaws very well making them ideal to use as a garnish. Simply place individual slices on a baking sheet and freeze until solid then store in freezer proof bags. Alternatively, cover with a sugar syrup before freezing in rigid containers.
Kiwi fruit in Cooking
Due to the enzyme called Actinidin, Kiwi fruit it a natural meat tenderiser and cooks have therefore utilised it in savoury as well as sweet recipes. It works by breaking down the protein. The most simple way is to just cut in half or mash the flesh, rub it over meat, and leave to stand for at least 15 minutes but do not marinate for more than 30-40 minutes. It should be remembered that this enzyme also breaks down protein in other foods such as gelatine and dairy products so when it is combined with ice cream, yogurt, or sour cream, it's best to consume it relatively quickly. Cooking halts the protein break-down process. Avoid using raw Kiwi fruit in dishes containing gelatine as it will impair the setting qualities.
Beef with Kiwi Sauce - Serves 4
450g/1lb Rump or Fillet Steak,
2 Kiwi fruit
1/2 Onion, roughly chopped
1 teasp freshly grated Root Ginger
1 Apple, roughly chopped
90ml/3fl.oz. Soy Sauce
90ml/3fl.oz. Rice Wine
1 tbsp Sugar
2 teasp Cornflour (cornstarch)
1. Preheat the grill to hot then grill the meat for 5-10 minutes on each side or until cooked to your taste
2. Meanwhile, peel the kiwi fruit, cut into quarters then place in a food processor together with the onion, ginger and apple and process until smooth.
3. Transfer to a small saucepan together with the soy sauce, rice wine and sugar and bring to simmering point, stirring constantly.
4. Mix the cornflour with a little water to make a slurry then add to the fruit mixture and cook, stirring constantly, until thickened.
5. Once cooked, cut the beef into 2.5cm/1 inch thick slices, catching any juices then add to the sauce and mix well. Adjust the seasoning to taste, adding more soy sauce if desired. Serve immediately with rice.