I saw this grape flavored apple at the store today. At first I thought it was some hybrid fruit and considered buying it. Then I looked closer. They actually inject the fresh apple with partly artificial grape flavor!
If this becomes a trend, we'll have to consider the kashrut of fresh fruit for the first time ever. (Outside of Israel, that is.) Imagine going to the house of a friend who doesn't keep kosher and seeing fruit on the table. Can we assume that it isn't injected with flavors that may not be kosher?
Of course, by posting this, I may be prompting a massive new chumrah hysteria in the frum community. If so, I want a cut of the profits from the hechsher industry. :-)