Miracle fruit

The term "miracle fruit" refers to three different plants:
 * Thaumatococcus daniellii – a species of tropical flowering plant known for being the natural source of thaumatin, an intensely sweet protein which is of interest in the development of sweeteners.
 * Gymnema sylvestre – Synsepalum dulcificum produces berries that, when eaten, cause sour foods (such as lemons and limes) subsequently consumed to taste sweet.
 * Synsepalum dulcificum – Gymnema sylvestre is a herb native to the tropical forests of southern and central India where it has been used as a naturopathic treatment for diabetes for nearly two millennia.

Probably in reference to Gymnema sylvestre
A medium sized oval berry, dark red in color, that grows on small bushy trees in tropical climates. Native to Africa, this berry is similar in shape to an olive and provides a meaty pulp surrounding a small seed. The distinct attribute of this berry is its ability to act as a sweetener, especially when eaten with sour ingredients, such as lemons, limes or vinegar. By eating this berry, the human taste buds are coated and converted to sensing only sweetness in foods, resulting in lemons tasting sweet and not sour, despite the fact that the flesh of this fruit is not sweet tasting. This sour dampening effect is present for an hour or so, but is sufficient for altering the taste of foods being served during a meal or a dessert. The characteristics of this berry enable it to be made into a sweetener for a variety of uses.