Research in the USA has discovered that tomatoes picked while still green and then coaxed to ripen while they are stored and transported at low temperatures, can have their flavour improved. Such tomatoes generally have poor flavour due to being chilled prior to ripening.
Dr Jinhe Bai, of the US Department of Agriculture, said: “Ideally, tomatoes should be picked ripe and then sold immediately. To produce better tasting tomatoes, we added a hot water pre-treatment step to the usual procedure that growers follow.”
In the tests, Florida-grown green tomatoes were dipped in water heated to 51.6 degrees C for five minutes and allowed to cool at room temperature. Only then were the fruit chilled to the temperatures normally used for transport. The scientists found that heating before chilling led to higher levels of flavour compounds in the tomatoes.
Dr Bai, on presenting this research at an American Chemical Society meeting in Boston, said; ”Chilling supresses production of oxygen, nitrogen and sulphur-containing heterocyclic compounds, ketones, alcohols and aldehydes, including 13 important aroma compounds of tomato flavour. But hot-water treated fruit actually produced higher concentrations of these important aroma contributors, even with subsequent chilling”.
Another technique which was discussed, involved treating half-ripened tomatoes with a plant growth regulator chemical, which also prevented flavour loss.