Following on from the success of its purple carrot last year, the UK retailer described the kumato as "naturally sweet" and "juicy" with the same nutritional benefits - and as high in the antioxidant lycopene as its red counterpart.
Developed in Aguilas, Spain over six years through natural cross-pollination, the kumato has a similar texture to its red sister but with a darker inner flesh and a much stronger and distinctive sweet taste.
The black version also has high levels of vitamin C. The novelty factor plus the non-GM aspect could well appeal to the increasingly demanding consumer.
Reports in the British press cite a Sainsbury's spokesman explaining that local consumer reactions were impossible to predict.
"There is an initial barrier to selling them in that people might be put off by the colour," she said. "But they are super sweet and in blind tests amongst our staff against the red tomato, they won hands down."
So can the consumer expect to soon see a 'black is back' array of products on the supermarket shelves ? Late last year the Danish ingredients company Chr Hansen launched a new black natural colour onto the market in a move designed to tap into the growing natural colours market.
The company spent one year in the laboratory formulating the free-flowing liquid CapColor CV-WSS that it maintains is a fitting alternative to the messy natural colour Carbo vegetabilis - a carbonised vegetable matter - traditionally used by manufacturers.
"Our expectations of CapColor CV-WSS is that by releasing such a new inventive product our whole Natural Colours business will expand, as it also creates possibilities for creating new colours by mixing it with our other CapColor range," Annette Moellgaard, marketing manager at Chr Hansen told FoodNavigator.com at the time.