Over recent years, many modern varieties of tomatoes have lost their original taste as selection for flavor has been over looked in favor of selection of qualities such as firmness and size for shipping purposes. Genetic analyses has now pinpointed which genes are required to reinstate the original rich flavor of tomatoes, now absent in the varieties of this fruit on many grocery store shelves.

Denise Tieman and her colleagues set out to identify the flavor infusing genes that have been lost. To achieve this, they sequenced the whole genomes of 398 wild, heirloom, and modern varieties of tomato. A consumer panel also rated 160 tomato samples representing 101 varieties on qualities such as flavor intensity and overall liking. As a result, dozens of chemical compounds of interest were identified by the consumer analysis.

The researchers used this information to isolate 13 chemical compounds associated with flavor that were reduced considerably in modern varieties relative to heirloom varieties. They then applied genetic sequencing data to identify the corresponding lost genes.

Among other results, Tieman’s group found that smaller fruit tended to have greater sugar content. This indicates that while selection for bigger tomatoes allowed domesticated tomatoes to grow bigger, it reduced both the sweetness and flavor.

The study was published in the journal Science.