You might be right about forbidden fruit, but Apples aren't mentioned in Genesis at all. It turns out that the first reference to the Apple in the Torah is this:
Friends
5 Who is this coming up from the wilderness
leaning on her beloved?
She
Under the apple tree I roused you;
there your mother conceived you,
there she who was in labor gave you birth.
http://www.biblegateway.com/passage/?search=Deuteronomy+32:1...
Based on 40% of the verses in the Bible that mention Apples being in the Song of Solomon, Apple is definitely a naughty little fruit. :D