How to change or delete Text appended to <title> tags

[Whispar1]

I am running 1.5.3.1  and Prestashop adds text to the end of all <title> meta tags.

 

For instance: I may have a title like this: 

<meta property="og:title" content="Alanna 6-Light Pendant - Whispar Design"/>

I usually leave the title section in the BO blank in order to use the product name as the title. Why does Prestashop add "Whispar Design" to the title tag. Where can this be changed so that is does NOT add this?

Ideally, for SEO purposes, I would like to control what is automatically added.

Edited May 8, 2014 by Whispar1 (see edit history)

[Whispar1]

Found the answer thanks to DH42!

http://blog.dh42.com/prestashop-meta-titles/

$meta_tags['meta_title'] = $default_value.' - '.Configuration::get('PS_CATEGORY_SHOP');

So if I wanted instead, to have it display say the category name instead of the shop name, what would be the correct syntax to do this?