The Miracle Fruit (Synsepalum dulcificum) is known for its miraculous berry.
When eaten, this berry causes sour foods (like a slice of lime) to taste sweet like lemonade. It also causes bitter foods to taste more palatable.
The effect is due to a molecule in the plant called “miraculin“. This molecule binds to the taste buds on your tongue. The effect lasts 30-60 minutes — it wears off when the miraculin is washed out of the mouth by salivation.
The miracle berry itself tastes mildly sweet, and it has low sugar content.
You can find Miracle Fruit powder on Amazon. I recommend using the powder rather than the tablets — the tablets are grainy and don’t dissolve easily.
This article describes the use of Miracle Fruit in dieting.
Two More “Miracle Fruits”
There are two other species of plant that have similar effects — Gymnema sylvestre — called “sugar destroyer” — makes sweet perception disappear — and Thaumatococcus daniellii — called “serendipity berry” — makes foods taste sweet).