We thought we had it all figured out. For maximum flavour, tomatoes should not go in the fridge with other fruit. It's what the science seemed to show. Except now, it seems there's a juicy alternative.

A contentious new study suggests it might not matter where we put this fruit so long as it's picked when ripe. Whether in a fridge or a bowl, the data seem to show the tomato will taste the same.

Bringing together a panel of experienced tomato tasters, researchers had the experts assess  several breeds and cross-breeds of tomatoes, each of which was stored for four days at room temperature, or four days in the fridge at 7 °C (44 °F).

During this process, the panel was trained to objectively score slices of tomato against a list of eight attributes, including colour, sweetness, sourness, aftertaste, and juiciness.

Contrary to what you'd expect, in the end the panel could not detect any flavour difference between tomatoes kept in the fridge and those left at room temperature.

In addition to the tongues of a dozen human experts, the team put the tomatoes through a run of other lab tests to measure volatiles, carotenoid levels, and sugar concentrations. They even used a fancy ASTREE Electronic Tongue for good measure.

"The shorter the storage period, the better it is for the flavour and related attributes," says crop scientist Elke Pawelzik from the University of Göttingen in Germany.

"However, we were able to show that, taking into account the entire post-harvest chain, short-term storage of ripe tomatoes in the refrigerator did not affect the flavour."

Unlike previous studies, which found refrigeration had a negative impact on a tomato's flavour, the fruits used in Pawelzik's research were tracked throughout the post-harvest process. 

This means the tomatoes were harvested ripe, spent one day at the distributor and then two days at the retailer before finding their way to the kitchen (or in this case, the lab).

This could be a reason why the new study has found such different results to previous data. It could also be that the tomatoes in this updated research were not kept in the fridge for as long as other studies, which lasted a week or so.

But there is another explanation. The fact that refrigerated tomatoes didn't taste any different may also have something to do with the actual variety of tomato.

"Our results indicate that the behaviour of the fruit during cold storage (7°C) is also strongly dependent on the cultivar/breeding line," the authors write.

"For example, the up- or down-regulation and restoration of volatiles… underlines the great impact of the cultivar on the flavor of the fruits and the acceptance by the consumer." 

These volatile compounds are what's thought to contribute to a tomato's flavour, and in the past, studies have suggested refrigeration dramatically reduces their presence.

But perhaps that's more the genes talking. People say they've noticed tomatoes have gotten less flavourful and juicy over the years, and research has shown modern cultivars are not well liked, even when they are harvested fully ripe and transported under ideal conditions. So, essentially, perhaps the fridge is not to blame at all.

It's an interesting idea, but further research needs to be done to figure out exactly how to store tomatoes best. Perhaps cold storage is a good thing, but only for a few days. Or maybe it doesn't matter at all and what we should really be doing is coming up with a better tomato itself.

"We showed that flavor is severely dependent on the cultivar and that crossing cultivars with enhanced flavor perception is a valuable step to improve flavor perception," the authors write.

"The next step is to look on the entire transportation route from the producer to the consumer, finding a way to preserve the flavor of the tomato fruits."

The study was published in Frontiers in Plant Science.