Science·Q&A

Scientists have a plan to make tomatoes great again

Research published on Thursday has identified the genes required to restore flavour to the once-proud tomato.

Flavour has been lost through years of selective breeding, but genetics might bring it back

New research lays out a clear genetic roadmap to restoring the flavour of tomatoes. (Elaine Casap / Unsplash )

You've noticed it: tomatoes don't taste anything like they used to. In this author's opinion, they've turned into a soggy, red, gooey, watery mess. 

But there's hope. Research published today in the journal Science has identified the genes required to restore flavour — and there is a clear road map to restoring what was lost decades ago.

What happened to the tomato?

It was really one of the first casualties of large-scale agricultural selective breeding. Agricultural companies and mass producers started breeding the tomato in the 1960s for desirable characteristics.  

Firmness helped them ship tomatoes longer distances. Size yielded higher prices. But flavour was left behind, leading to a slow, almost imperceptible decline in taste. The result is the tomatoes we see on the shelves today. 

Large-scale agricultural selective breeding often favours firmness and size over flavour. (Flickr / GoToVan)

What are scientists planning to do about it?

An international group of scientists looked at 160 tomato samples from 101 varieties, ranging from modern store-shelf ones to wild, heirloom tomatoes, and asked a bunch of tomato aficionados to rate them based on overall liking and flavour intensity.

From that data, they could narrow down which chemicals in the more-desired tomatoes were actually responsible for the preferred flavour. 

Dozens of flavour compounds were identified, and scientists eventually whittled the group down to 13 different chemicals that were found to be higher in tastier tomatoes.

How does identifying flavour compounds improve the tomato?

That's where genomics — sequencing and analysis of an organism's genome — comes in. Researchers say they were able to identify the specific genes involved in making those 13 different flavour compounds.

One of the reasons tomatoes have lost their flavour is because these compounds are present in very small amounts. The concentration is so small that they are almost undetectable by chemical profiles but definitely detectable by our taste buds. That means that small tweaks in concentration can drastically improve the flavour.

Harry Klee, one of the lead researchers from the University of Florida, helped identify the flavour compounds that make tomatoes tasty. (University of Florida / Tyler Jones)

The plan is to use this new genetic knowledge to help breeders produce higher concentrations of desirable flavour compounds. The hope is that the tomato can still have the durability and size that the commercial producers want but also the flavour consumers desire.

There are some hurdles though — boosting sugar content and maintaining size may be a problem. Here's how Harry Klee, one of the lead researchers from the University of Florida, explains it: 

"Sugars are a challenge because we know that the only way you're going to get more sugar is to reduce the yield or reduce the size of the fruit… There's going to be a trade-off." 

But, let's face it, most of us would be more than willing to buy smaller tomatoes if they have double the flavour.

When can we expect to see these improved tomatoes?

The experiments are already underway. Klee expects that within two years the more flavourful tomato will be ready for commercial viability testing.

It should be noted that there's a huge caveat to all this work: no matter what tomato you buy, even a fancy homegrown organic, wild, heirloom tomato will lose all flavour if you put it in the refrigerator. So if you love your tomatoes but store them in the fridge — the blame rests on you!

ABOUT THE AUTHOR

Torah Kachur

Science Columnist

Torah Kachur has been the syndicated science columnist for CBC Radio One since 2013. Torah received her PhD in molecular genetics from the University of Alberta and studied how worm gonads develop. She now teaches at the University of Alberta as a contract lecturer in cell biology and genetics.