At a time when orange cauliflower and white strawberries are now common sights in American grocery stores, a non-yellow pineapple doesn’t seem all that out of place. Still, I wondered: Why now with the flashy presentation? And why pink?
Pineapples happen to naturally convert a reddish-pink pigment called lycopene, which is high in antioxidants, into the yellow pigment beta-carotene. (Lycopene is what gives tomatoes and watermelon their color.) Preventing this process, then, could yield pink flesh and higher antioxidants. The company set its dedicated pineapple research team to the task of figuring out how to do it.
The team landed on a set of three modifications to the pineapple genome. They inserted DNA from a tangerine to get it to express more lycopene. They added “silencing” RNA molecules to mute the pineapple’s own lycopene-converting enzymes, which also helped reduce its acidity. (RNA silencing is the same technique used to make non-browning GMO Arctic apples.) Finally, Del Monte added a gene from tobacco that confers resistance to certain herbicides, though representatives for the company say this was simply so its scientists could confirm that the other genetic changes had taken effect—not because Del Monte plans to use those herbicides in production.
