It turns out berry is actually a botanical term, not a common English one. Blackberries, mulberries, and raspberries are not berries at all, but bananas, pumpkins, avocados and cucumbers are. So...
The fruit of the Synsepalum dulcificum plant has been dubbed ‘miracle berry’ for its amazing ability to make sour foods taste sweet when consumed. This effect is due to miraculin, a glycoprotein...