According to this [url=https://www.nytimes.com/2012/06/29/science/flavor-is-the-price-of-tomatoes-scarlet-hue-geneticists-say.html]article about tomatoes[/url] in the NYTimes, scientists have discovered the reason why commercial tomatoes aren't as sweet as they could be. Seventy years ago breeders altered tomatoes so that they ripened to a uniform red color. However in doing so they turned off a gene responsibile for sugar production within the fruit, causing it to be 20 - 30% less sweet.
[quote]...in a paper published in the journal Science, researchers report that the very gene that was inactivated by that mutation plays an important role in producing the sugar and aromas that are the essence of a fragrant, flavorful tomato.
“That mutation has been introduced into almost all modern tomatoes. Now we can say that in trying to make the fruit prettier, they reduced some of the important compounds that are linked to flavor.â€