I believe the title of the book you recall is Who's Got the Apple? by Jan Loof.
"Story of the "ripening" of a very green apple on the windowsill."
"Picture of man with opaque glasses carrying apple while being watched
by a dog and a small girl holding a teddy on the front cover."
Publisher: Random House, New York
Publication Date: 1975
Binding: Soft Cover
A Kid's Review
"First, the Man in the Black Hat gets a fake apple while doesn't know
it is real because a grocer played an April Fools joke on him. For
example, he sits the apple on a windowsill to try and ripen it.
Second, the apple gets pushed out the window by the Man in the Black
Hat's parrot. Through out the book the Man in the Black Hat did not
know that apple was ever go. Last at the end of the book a bug, ripe
apple is accidentally returned in the place of the fake apple, with
only a bite mark out of the apple. The Man in the Black Hat never knew
the apple was gone. For example, he blamed his parrot for the bite
mark in the apple, while a fireman really took the bite. I have had
this book since I was little and years later still read and enjoy
Who's Got the Apple."
Purchase a copy of this book on Amazon
"adventures of an apple"
I hope this helps!