If you're going through customs and having all your stuff inspected (as you will be) it shouldn't matter as you'll have all your bags with you. However, if you want to speed things up, have them readily available, in a separate plastic bag. If you have a piece of fruit loose in your luggage, they'll likely want to check the rest of your luggage to make sure none has gotten further down.
The inspect and release is probably to look for insects or seeds, so once they're satisfied, you'll get it back.
Note that if you're at all unsure, ALWAYS declare. Failing to declare something as seemingly innocuous as a piece of fruit in some places (Aus, NZ) can get you a sizeable fine - enough to put a dampener on your trip. Yes you're going through Canada and the US, but check their customs signs and anything you're uncertain on - check with them.
Hot tip: I've heard and seen people declaring stuff to speed up their trip through customs - by going in the short 'declare' line and declaring something that is clearly not a problem (like prescription medicine) they get waved straight on through and out faster than anyone in the 'normal' line!