I learned a long time ago never to edit php files with the editor available in the webmaster panel. I assume you're using CPanel (since that's pretty common). The editor does terrible things to php. I'm glad you got that sorted.
You change that information in meta_tags.php (see the lines I highlighted in red).
Code:
<?php
/**
* @package languageDefines
* @copyright Copyright 2003-2007 Zen Cart Development Team
* @copyright Portions Copyright 2003 osCommerce
* @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
* @version $Id: meta_tags.php 6668 2007-08-16 10:05:09Z drbyte $
*/
// page title
define('TITLE', 'Zen Cart!');
// Site Tagline
define('SITE_TAGLINE', 'The Art of E-commerce');
// Custom Keywords
define('CUSTOM_KEYWORDS', 'ecommerce, open source, shop, online shopping');