How to locate a particular piece of code in my theme settings?

I need to locate a piece of code in my theme settings and would like some advise on how to find it. I went to my admin/appearance/editor and searched for this zp_cpt.php but could not locate it.
I need to add some SEO settings into this code below:
$portfolio_custom_default = array(
'supports' => array( 'title', 'editor', 'thumbnail', 'revisions', 'excerpt'),
'menu_icon' => get_stylesheet_directory_uri().'/include/cpt/images/portfolio.png',

is there an easy way to find something like this?