https://www.vox.com/2015/7/28/9050469/watermelon-breeding-paintings, posted 26 Jun by peter in art food history nature
The watermelon originally came from Africa, but after domestication it thrived in hot climates in the Middle East and southern Europe. It probably became common in European gardens and markets around 1600. Old watermelons, like the one in Stanchi's picture, likely tasted pretty good — Nienhuis thinks the sugar content would have been reasonably high, since the melons were eaten fresh and occasionally fermented into wine. But they still looked a lot different.
That's because over time, we've bred watermelons to have the bright red color we recognize today. That fleshy interior is actually the watermelon's placenta, which holds the seeds. Before it was fully domesticated, that placenta lacked the high amounts of lycopene that give it the red color. Through hundreds of years of domestication, we've modified smaller watermelons with a white interior into the larger, lycopene-loaded versions we know today.
Of course, we haven't only changed the color of watermelon. Lately, we've also been experimenting with getting rid of the seeds — which Nienhuis reluctantly calls "the logical progression in domestication." Future generations will at least have photographs to understand what watermelons with seeds looked like. But to see the small, white watermelons of the past, they too will have to look at Renaissance art.