User blog comment:Plainblack/Blackbeard, the Enigma/@comment-10543621-20130904061618/@comment-10923326-20130904114654

Doffy probably knew that Ace's fruit was an apple, he also thought that Ace would die at the execution stand, although Ace died anyway. Therefore, he brought the apple and kept it under his fuzzy jacket.

Or, he sent his men around the world to find the fruit :S