Actually the Bible does not state that an apple was eaten but it makes it clear that it was a literal fruit.
Genesis 3:1-6 (New International Version, ©2010)
1 Now the serpent was more crafty than any of the wild animals the LORD God had made. He said to the woman, “Did God really say, ‘You must not eat from any tree in the garden’?”
2 The woman said to the serpent, “We may eat fruit from the trees in the garden, 3 but God did say, ‘You must not eat fruit from the tree that is in the middle of the garden, and you must not touch it, or you will die.’”
4 “You will not certainly die,” the serpent said to the woman. 5 “For God knows that when you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”
6 When the woman saw that the fruit of the tree was good for food and pleasing to the eye, and also desirable for gaining wisdom, she took some and ate it. She also gave some to her husband, who was with her, and he ate it.
This should be interpreted as much more than a quaint children's story.It actually documents Satan's ,here in the form of a serpent ,first use of a deceitful ploy that now goes under the name of "Once Saved Always Saved";the sales pitch that you can ignore God's rules,do whatever you want to do in your selfish interests and get away with it because of course God won't care one single bit since He loves us so much we are told.