Ely, Cambridgeshire food company Isleham Fresh Produce is growing a crop of purple carrots, which are due to hit the shelves of UK grocery giant Sainsbury in July at a slightly higher price than their orange cousins.

The violet veggies are actually closer to the original carrots first grown in the Middle and Far East, the supermarket supplier said yesterday [Thursday]. Carrots have only been orange since the 1720s, when the Dutch decided to cultivate a crop in their national colour.

The purple carrots, which are still orange on the inside, contain purple-red pigments called anthocyanins. Scientists have attributed the pigments with anti-oxidant powers that provide extra protection against some forms of cancer and heart disease.

Sainsbury’s believes that the new colour will encourage children to eat more carrots. The retailer’s root buyer, Russell Crowe, told CNN: “Hopefully, this unusual colour will influence children to eat more vegetables while parents can rest assured that there is nothing artificial about the carrots.”

Isleham Fresh’s technical manager Mark Spurdens told BBC radio: “They’re different. They’ve had a little bit of extra care and attention in the way they’ve been raised. They do taste quite sweet.”

The company also grows carrots in white and black, and aims to produce a rainbow selection for Sainsbury’s shelves next year.