Tesco has ramped up it exotic produce offer with two new vegetables - one of which is a purple potato.

The Purple Jewel sweet potato, which is described as having a creamy and nutty taste, hits shelves this week and will be joined by Inca roasting potato Mayan Queen, not previously available in Britain. The two varieties will go into 100 stores.

"My aim is to find exotic types of potato and to try and get them grown in the UK, which is what we're already doing with Mayan Queen," said Tesco potato buyer Jonathan Corbett.