Word for the person who has a favorite
The apple has a fanbase of 2.
or
Jack and Jill are apple fans.
From TheFreeDictionary.com:
Fanbase [ˈfænˌbeɪs]
n
"the body of admirers of a particular pop singer, football team, etc." (or fruit!)
There are are a number of words which might fit well, depending on the context. Here's a few that strike me as particularly appropriate for your example:
- appreciator
- fancier
- connoisseur
For example,
Jack and Jill are both apple connoisseurs.
There were two apple fanciers in the room.