| Synsepalum dulcificum | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Ericales |
| Family: | Sapotaceae |
| Genus: | Synsepalum |
| Species: | S. dulcificum |
| Binomial name | |
| Synsepalum dulcificum (Schumach. & Thonn.) Daniell |
|
| Synonyms | |
|
Bakeriella dulcifica (Schumach. & Thonn.) Dubard |
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Synsepalum dulcificum is a plant with a berry that, when eaten, causes sour foods (such as lemons and limes) subsequently consumed to taste sweet. This effect is due to miraculin, which is used commercially as a sugar substitute. Common names for this species and its berry include miracle fruit[2], miracle berry, miraculous berry,[2], sweet berry,[3][4][5] and in West Africa where the species originates agbayun,[6] taami, asaa, and ledidi.
The berry itself has a low sugar content[7] and a mildly sweet tang. It contains a glycoprotein molecule, with some trailing carbohydrate chains, called miraculin.[8][9] 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 theory is that miraculin works by distorting the shape of sweetness receptors "...so that they become responsive to acids, instead of sugar and other sweet things."[10] This effect lasts until the protein is washed away by saliva (up to about 60 minutes).[11]
The names miracle fruit and miracle berry are shared by Gymnema sylvestre and Thaumatococcus daniellii,[2] two other species of plant are used to alter the perceived sweetness of foods.
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The berry has been used in West Africa since at least the 18th century, when European explorer Chevalier des Marchais,[12] who searched for many different fruits during a 1725 excursion to its native West Africa, provided an account of its use there. Marchais noticed that local people picked the berry from shrubs and chewed it before meals.
An attempt was made in the 1970s to commercialize the ability of the fruit to turn unsweet foods into sweet foods without a caloric penalty, but ended in failure when the U.S. Food and Drug Administration (FDA) classified the berry as a food additive.[7] 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.[13] The FDA has always denied that pressure was put on it by the sugar industry, but refused to release any files on the subject.[14] 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.[10] The idea of the "miraculin party"[10] was conceived then. Recently, this phenomenon has enjoyed some revival in food-tasting events, referred to as "flavor-tripping parties" by some.[15] The tasters consume sour and bitter foods, such as lemons, radishes, pickles, hot sauce, and beer, to experience the taste changes that occur.
The plant is a shrub that grows up to 20 feet (6.1 m) high in its native habitat, but does not usually grow higher than ten feet in cultivation. Its leaves are 5-10 cm long, 2-3.7 cm wide and glabrous below. They are clustered at the ends of the branchlets. The flowers are brown. It carries red, 2 cm long fruits. Each fruit contains one seed.[4]
The plant grows best in soils with a pH as low as 4.5 to 5.8, in an environment free from frost and in partial shade with high humidity. It is tolerable to drought, full sunshine and slopes.[4]
The seeds need 14 to 21 days to germinate. A spacing of 4 m between plants is suggested.[4]
The plants first bear fruit after growing for approximately 3-4 years,[4] and produce two crops per year, after the end of the rainy season. This evergreen plant produces small, red berries, with white flowers and are produced for many months of the year.
The seeds are about the size of coffee beans. Without the use of plant hormones, the seeds have a 24% sprouting success rate.
In Africa, leaves are attacked by lepidopterous larvae, and fruits are infested with larvae of fruit-flies. The fungus Rigidoporus microporus has been found on this plant.[4]
Miraculin is now being produced by transgenic tomato plants.[16][17]
In tropical West Africa, where this species originates, the fruit pulp is used to sweeten palm wine.[18] Historically, it was also used to improve the flavor of maize bread gone sour.[6]
Attempts have been made to create a commercial sweetener from the fruit, with an idea of developing this for diabetics.[12] 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.[12] This claim has not been researched scientifically,[12] 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.[11]
In Japan, miracle fruit is popular among diabetics and dieters.[8][9]
Today, it is being cultivated in Ghana, Puerto Rico, Taiwan, and South Florida.[4]
The shelf life of the fresh fruit is only 2–3 days. Because miraculin is denatured by heating, the pulp must be preserved without heating for commercial use. Freeze-dried pulp is available in granules or in tablets, and has a shelf life of 10 to 18 months.