First you should read the Codex entry on domain moving
But in a nutshell: aside from moving your contents phisically to the /blog location, all you have to do is search and replace every SQL entry for the previous domain (instead of just changing the domain in Wordpress options). Doing this by hand is pretty dangerous, I found this script to be very helpful:
Backup your database (eg. with PHPMyAdmin) in SQL form, then upload the above php script to your host folder, and point your browser to it. Using it you can safely search & replace http://blog.wordfruit.com to http://wordfruit.com/blog.
All your post contents and options will be then rewritten to the new domain. What possibly could remain is your page template - if you made it yourself, I'd also download and search the contents the theme folder for possible hard links to the old domain.