The History

Synsepalum dulcificum is a plant species that originates from West Africa. The plant and its fruit are also known as miracle fruite, miracle berry, and miraculous berry. In Africa, they call it agbayun, taami, asaa, and ledidi. The plant is a shrub with dark green dense foliage. It grows best in soils with low pH and an environment with high humidity. It can also survive during long periods of low rainfall, full sunshine and slopes. It takes 3 to 4 years for the plants to bear fruit. They may produce two crops per year. The plant produces white flowers and small red berries. It is best known for its berry which is a taste modifier.

The small red berry alters the taste of acidic foods like lemons and limes making them taste sweet. It contains a glycoprotein called Miraculin which is not sweet itself and even has low sugar content. The protein chains to the tongue’s taste buds causing the bitter foods to taste sweet. The neutral pH binds and blocks the receptors, while the low pH miraculin binds proteins activating the sweet receptors in the tongue. The effect may last 30 minutes to an hour until the saliva washes it away. It is not the only plant species that is known as a miracle fruit, Gymnema sylvestre and Thaumatococcus daniellii are also known to alter the perceived sweetness of acidic foods.

The miracle fruit was first registered by explorer Chevalier des Marchais during his excursions in the 18th century. Experiments were conducted by the Dutch and Japanese to separate and refine the active glycoprotein in the 1960s. The berry was sequenced in 1989 and was found to consist of 191 amino acids and a variety of sugars. Its sugars consist of glucosamine, mannose, fucose, xylose, and galactose. This was found in the Swiss-Prot biological database of protein sequences. The native state of miraculin is a tetramer consisting of two dimers, each held together by a disulfide bridge. Miraculin is part of the Kunitz STI protease inhibitor species.

In Africa, they use miraculin as a sweetener and flavoring agent for beverages and foods. They use its fruit pulp for cocktails drinks, beers, vinegar and pickles. It also used to sweeten palm wine. Miraculin has been experimented to express it in yeast and tobacco plants but researchers have failed. They have been successful in preparing genetically modified E. coli bacteria, lettuce, and tomatoes that express the glycoprotein, miraculin. Resulting in 40 micrograms of miraculin per gram of lettuce leaves. Two grams of lettuce leaves produced about the same amount of miraculin as one berry.

The miracle fruit was used in the United States in the 1980s. They tried to commercialize the fruit for its ability to turn sour foods to sweet without a caloric cost. It was also sold as a diet pill in the 1970s. There were tasting events where people consumed sour foods and experienced the taste modifying activity of the glycoprotein turning the foods sweet.