Enhancing the taste and shelf life of tomatoes

Tomatoes -  the world’s favourite fruit - may be tasty as they are, whether fresh or cooked. But researchers say they may be able to improve the flavour and shelf life of this ubiquitous fruit. A UK research on the purple GM varieties holds the key.

"Working with GM tomatoes that are different to normal fruit only by the addition of a specific compound, allows us to pinpoint exactly how to breed in valuable traits," says Professor Cathie Martin from the John Innes Centre.

The research could also lead to GM varieties with better flavour, health and shelf life characteristics because even higher levels of the compounds can be achieved.

In research to be published in Current Biology, Prof Martin and colleagues studied tomatoes enriched in anthocyanin, a natural pigment that confers high antioxidant capacity. The purple GM tomatoes have already been found to prolong the lives of cancer-prone mice and in the latest findings they also more double the normal shelf life of tomatoes from an average of 21 days to 48 days.

"Post-harvest losses due to rotting are such a serious problem for growers and supermarkets that even an increased shelf life of one day would make an enormous difference to them," said Yang Zhang, lead author from the John Innes Centre.

One way to improve shelf life is to pick tomatoes early when they are still green and induce them to ripen artificially with ethylene. However, this results in loss of flavour. Another method is to grow varieties that never fully ripen, but these also never develop a full flavour.

In the current study, anthocyanins were found to slow down the over-riNike Paul George PG1