Post title shows blog title

please tell me how can I remove blog title from single post titles in search engine.
Like recently I published a post, you can see this here – proxy sites with a title Free proxy sites to surf internet anonymously on my site top5blog.com and in the search results it is showing like this :
Free proxy sites to surf internet anonymously – top5blog
I need to remove this top5blog.
/%postname%/ – this is what I have chosen for permalink. Tell me how can I correct it.