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Tuesday, December 22, 2009

What is this so-called Miracle Fruit ?



[Extracted from Wikipedia....the free encyclopedia]

The miracle fruit, or miracle berry plant (Synsepalum dulcificum), produces berries that, when eaten, cause sour foods (such as lemons and limes) subsequently consumed to taste sweet. The berry, which contains active polyphenols was first documented by explorer Chevalier des Marchais who searched for many different fruits during a 1725 excursion to its native West Africa. Marchais noticed that local tribes picked the berry from shrubs and chewed it before meals. The plant grows in bushes up to 20 feet (6.1 m) high in its native habitat, but does not usually grow higher than ten feet in cultivation, and it produces two crops per year, after the end of the rainy season. It is an evergreen plant that produces small red berries, with flowers that are white and which are produced for many months of the year. The seeds are about the size of coffee beans.

The berry itself has a low sugar content and a mildly sweet tang. It contains an active glycoprotein molecule, with some trailing carbohydrate chains, called miraculin. When the fleshy part of the fruit is eaten, this molecule binds to the tongue's taste buds, causing sour foods to taste sweet. While the exact cause for this change is unknown, one hypothesis is that the effect may be caused if miraculin works by distorting the shape of sweetness receptors "so that they become responsive to acids, instead of sugar and other sweet things". This effect lasts 15–60 minutes.



History

An attempt was made in the 1970s to commercialize the ability of the fruit to turn non-sweet foods into sweet foods without a caloric penalty, but ended in failure when the FDA classified the berry as a food additive. There were controversial circumstances with accusations that the project was sabotaged and the research burgled by the sugar industry to prevent loss of business caused by a drop in the need for sugar. The U.S. Food and Drug Administration (FDA) has always denied that pressure was put on it by the sugar industry, but refused to release any files on the subject. Similar arguments are noted for the FDA's regulation on stevia now labeled as a "dietary supplement" instead of a "sweetener".

For a time in the 1970s, US dieters could purchase a pill form of miraculin. It was at this time that the idea of the "miraculin party" was conceived. Recently, this phenomenon has enjoyed some revival in food tasting events, referred to as "flavor tripping parties" by some. The tasters consume sour and bitter foods, such as lemons, radishes, pickles, hot sauce, and beer, to experience the taste changes that occur.



General information and cultivation

The plant grows best at a pH as low as 4.5 to 5.8, in an environment free from frost and in partial shade with high humidity. Without the use of plant hormones or electricity, the seeds have a 24% sprouting success rate. However, it can be around 80% if planted immediately.[citation needed] The plants first bear fruit after growing for approximately 2–3 years.[citation needed]

Attempts have been made to create an artificial sweetener from the fruit, with an idea of developing this for diabetics. Fruit cultivators also report a small demand from cancer patients because the fruit allegedly counteracts a metallic taste in the mouth that may be one of the many side effects of chemotherapy. This claim has not been researched scientifically, though in late 2008, an oncologist at Mount Sinai Medical Center in Miami, Florida began a study and by March 2009 had filed an investigational new drug application with the U.S. Food and Drug Administration.

In Japan, miracle fruit is popular among diabetics and dieters.

In 2006, researchers at the University of Tsukuba genetically engineered lettuce to produce large amounts of miraculin. The scientists' crops resulted in 40 micrograms of miraculin per gram of lettuce leaves, which was considered a large amount. Two grams of lettuce leaves produced roughly the same amount of miraculin as in one miracle fruit berry. The researchers said others had unsuccessfully used bacteria, yeast and tobacco plants.



Freeze-dried form

Miracle fruit is available as freeze-dried granules or in tablets — this form has a longer shelf life than fresh fruit. Tablets are made from compressed freeze-dried fruit which causes the texture to be clearly visible even in tablet form.

Freeze-dried miracle fruit is now widely available on the Internet.

Limitations

Miraculin is a non heat-stable protein, subject to denaturation from heating and thus miracle berries are not taste-bud active when cooked.

While Miraculin changes the perception of taste, it does not change the food's chemistry, leaving the mouth and stomach vulnerable to the high acidity of some foods, such as lemon juice, which may cause irritation if eaten in large quantities.

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