Comment 4 for bug 1295323

According to there are two ways of disabling baloo:

1) Add your home folder to the list of not indexed folders in the Desktop Search KCM (System Settings -> Desktop Search)

$ cp /usr/share/autostart/baloo_file.desktop ~/.kde/share/autostart/
$ echo "Hidden=True" >> ~/.kde/share/autostart/baloo_file.desktop

I did not like the first option because the addition of paths is somewhat broken. The second seems to work better - after restart I do not see baloo among running processes.