Miracle fruit (
Synsepalum dulcificum)
is the botanical source of miraculin and an understudied tropical fruit
species with potential as a natural, noncaloric sweetener. Miraculin
changes the perception of sour (acidic) foods and beverages to sweet by
temporarily modifying taste receptors on the tongue.
1
At Florida State
University in Tallahassee, a professor of biophysics. Dr. Lloyd
Beidler, began his studies of miracle fruit in the late 1950's.
Together with Dr. Kenzo Kurihara, he successfully isolated the active
principle, publishing their results in "Science", Vol. 161, September
20, 1968. Research performed independently in the Netherlands under the
sponsorship of the Unilever Company culminated in the same year. It was
found that a glycoprotein causes the taste-modification effect, a
giant, 'macro-molecule' with a molecular weight of 44/000. The size of
this molecule made it difficult, if not impossible, to synthesize it.
This was one of the reasons I. M. C. had determined that the miracle
fruit had no real commercial potential; vast plantations would have
been necessary to supply enough fruit for the large scale production
they envisioned.
2
Drs. Beidler and Kurihara had access to a
sufficient number of fresh berries, which were grown in a greenhouse at
the university. The miracle fruits were stored in the deep freeze until
needed; 300 at a time were used to make a potent solution through
standard scientific procedures. Through their thorough tests, they
discovered that the taste-modifying activity was destroyed by heat, or
when exposed to organic solvents, and was greatly reduced by exposure
to pH above 12.0 or below 2.5 at room temperature. Situations with a pH
of 3.7 and temperature of 4°C caused the activity to remain
stable for one month.
2
It was also concluded that the protein was
basic, and contains no other protein within the active component. It
does have bound to it two sugar molecules; the active principle
therefore contains a small amount of sugar—6.7%, which was
determined not to be an impurity. This is what makes the active
principle of
S.
dulcificum a glycoprotein. Glycoproteins are known to
be completely innocent of any toxicity and are readily metabolized by
the body.
2
Noncaloric,
natural sweeteners are increasing in popularity as a means to reduce
sugar content in foods and beverages. These natural sweeteners have
distinct flavor characteristics, strengths, and weaknesses including
metallic or other off flavors. Miraculin from miracle fruit is a
protein noncaloric, natural sweetener. The protein interacts with sweet
taste receptors on the tongue and increases the perception of sweetness
in the presence of an acid. Therefore, the perceived sweetness of foods
like lemons and strawberries is greatly increased without additional
sugar. The major strength of the miraculin as a noncaloric sweetener is
that its flavor profile is the closest to sugar when compared to other
natural sweeteners, and it is free from metallic off flavors.
1
Miraculin
has been well studied for its sweet-inducing properties. The overall
sweetening sensory impact is ~400,000 times that of sugar, though a
direct comparison is challenging. Miracle fruit and miraculin are
available through online vendors in multiple formats, including live
plants, fresh fruit, and freeze-dried fruit powder. Miraculin has also
been reported to reduce sugar without reducing the perception of
sweetness, improve insulin sensitivity, and reduce the metallic taste
of foods during administration of chemotherapy treatments. These
reports should be interpreted cautiously because many of these studies
included either small sample sizes or did not measure impacts in human
subjects.Therefore, miracle fruit should not be considered as a
treatment for disease and should not replace consultation with
competent medical professionals for legitimate health concerns.
1
Today,
miracle fruit can be sold as a natural product, but miraculin requires
additional safety assessment before it can be sold as a food or a food
additive. Purified miraculin is a relatively new product, and GRAS
(Generally Recognized As Safe) status is pending in the United States.
Preliminary attempts to obtain GRAS status for miraculin from the FDA
in the 1970s were denied due to lack of safety information (lack of
“substantial history of consumption of the substances by a
significant number of consumers in the United States,” US FDA
1977 Federal Register 42, 26467–26468). The rejection of GRAS
status for miraculin has become the subject of conspiracy theories and
a number of popular press stories pitting special-interest commodity
groups against miracle fruit.
1
The berry has been used in West Africa since at least the 18th century,
when a European explorer, the Chevalier des Marchais, provided an
account of its use there. Des Marchais, who was searching West Africa
for many different fruits in a 1725 excursion, noticed that local
people picked the berry from shrubs and chewed it before meals.
3