Jennifer Schultz Nelson
Extension Educator, Horticulture
I consider it quite a personal achievement to be able to say I thought something was cool long before Martha Stewart deemed it "a good thing". But I am proud to say I had a miracle fruit plant long before it appeared on her show.
Miracle fruit, Synsepalum dulcificum, is an evergreen shrub/small tree native to tropical West Africa. The "miracle" about this fruit is what happens after you eat it.
The plant produces small red oval-shaped berry that doesn't taste like much of anything itself. It's not sweet at all, but if you allow the juices and pulp to coat your mouth, sour or bitter foods will taste sweet. You can bite right into a big slice of lemon or lime without the pucker factor. Depending on how much of the fruit you consume, its taste effects can last minutes to hours.
What's this plant's secret? The molecule responsible for the miracle in this fruit is a molecule called miraculin. It is a glycoprotein, a protein molecule with sugar molecules attached. It was first isolated from miracle fruit in 1968 by a Japanese scientist.
Scientists still haven't figured out exactly how miraculin changes the perception of taste. One hypothesis says miraculin temporarily changes the receptors on our taste buds, so that the "sweet" taste receptors are activated by the acids in sour foods, and we perceive the taste as sweet.
The Japanese are investigating the potential of using miraculin as a sweetener in foods. They are focusing on using genetically modified organisms to produce miraculin in large quantities, since the miracle fruit plant only produces a crop twice a year. To date they have been successful in transferring the gene to produce miraculin into lettuce. By doing this they have a fast growing crop that also produces miraculin.
Currently, using miraculin as a sweetener is only approved in Japan. There, it is approved as a harmless food additive. On our shores, the Food and Drug Administration (FDA) has denied approval for use of miraculin as a sweetener in the U.S.
In its native West African habitat, miracle fruit will reach heights of up to about 20 feet tall. Grown in cultivation, it usually only grows to about 5 feet tall.
Miracle fruit has deep green, elongated leaves and produces small ¼ inch white flowers. It makes a great container plant. Since it is a tropical plant, here in Illinois it needs to be overwintered indoors.
When the plant is indoors, it needs the brightest location you can provide. When the weather warms, it loves to be outside, but in a lightly shaded location.
As a bonus to us, miracle fruit even loves high humidity! What a great plant for an Illinois summer. Humidity can be tough to provide indoors, but using a humidifier helps. Another method is to place a plastic bag loosely over the plant to hold moisture in.
Miracle fruit requires a well-draining acid soil to thrive. This can be achieved by using peat and perlite based planting mixes, and using fertilizers for acid-loving plants.
It is extremely important that miracle fruit never sits in waterlogged soil, as it will rapidly succumb to root rot. Be sure to check the soil before assuming the plant needs water.
I thought I had scooped Martha Stewart when I heard the miracle fruit plant had been featured on her show, long after I had purchased my own plant. My excitement quickly faded as my plant started to look sickly and died a slow agonizing death, despite extra TLC. Care guides about miracle fruit warn that plants will slowly die back and die completely when the pH is not acid enough. I probably also added to the trauma by watering it a bit too much as well.
But I will not give up on the miracle fruit just yet. Martha's endorsement has made them extremely hard to find in stock anywhere, but I will keep looking.