for an upcoming project we wanna translate our app to multiple languages. Having a look at Facebook\'s How-To: Open Graph Internationalization page, you get very detailed in
I answered my own question: here
You have to refresh the cache of facebook.
curl -X POST -F "id=http://yoururl" -F "scrape=true" -F "locale=fr_fr" "https://graph.facebook.com" -s
(in my example, I used fr_fr)