The ‘Indigo Rose’ tomato – so named because of its characteristic purple skin – is the first "really" purple variety to contain higher than normal levels of antioxidants.
Developed by a team of researchers that seek to breed tomatoes with high levels of antioxidants, at Oregon State University, USA, the new variety is said to be a novelty type intended for home gardens and the fresh market.
Professor Jim Myers of Oregon State said the tomato is the first improved variety in the world to contain anthocyanins in its fruit.
He explained that research into breeding of purple tomatoes containing the anthocyanins "will lead to a better understanding on how the antioxidants express in tomatoes and may contribute to human health."
"They have many varied effects on human health, but while they are powerful antioxidants in the test tube, we don’t really know whether they have an antioxidant effect in the human body," added Myers.
Purple tomato
Anthocyanins are in the class of flavonoids – compounds found in fruits, vegetables and beverages – that have aroused interest because of their potential health benefits.
Breeding of the Indigo Rose variety began in the 1960s, when two breeders – one from Bulgaria and the other from the United States – first crossed-cultivated tomatoes with wild species from Chile and the Galapagos Islands, explained Myers.
"The purple colour draws their interest and because it's extraordinary, people tend to expect impressive flavour as well,” said Myers, who noted that the new species “tastes just like a tomato.”
“Anthocyanins are essentially tasteless," he confirmed.
The new tomato is released as an open pollinated variety, and as such, seed saved from self-pollinated plants will grow true and not produce hybrids.
"It's also important to know that genetic engineering techniques are never used to develop these lines," Myers said. "These tomatoes are not GMO."