You may be surprised to see a rather unusual-looking fruit displayed among the apples and tomatoes next time you pop into Waitrose.

This week, the supermarket announced that it is introducing the cucamelon, a grape-sized fruit that looks a bit like a tiny melon but apparently tastes like sour cucumbers. Also known as the "mouse melon" or "sour gherkin", this tiny fruit is not some sort of weird hybrid; it actually originates from Mexico and Central America, where the locals have been eating them for thousands of years. Grow-your-own plants will be available for £4 from Waitrose - but it's not the only exotic new fruit around...

The kiwi berry