open this file
components/com_phocagallery/views/category/view.html.php
search for
$document->setTitle($params->get( 'page_title') . ' - '. $category->title);
you will find this line within
// Set page title per category
if ($tmpl['displaycatnametitle'] == 1) {
$document->setTitle($params->get( 'page_title') . ' - '. $category->title);
} else {
$document->setTitle( $params->get( 'page_title' ));
}
replace with
$document->setTitle($category->title);