add_filter('admin_init', 'my_general_settings_register_fields');
function my_general_settings_register_fields(){
    $custom_settings = array(
        array(
            'title'=>'Feedback email',
            'value'=>'feedback_email'
        )
    );

    foreach ($custom_settings as $value) {
        register_setting('general', $value['value'], 'esc_attr');
        add_settings_field($value['value'], $value['title'], 'my_general_settings_fields_html', 'general', 'default', array('option_name' => $value['value']));
    }
}

function my_general_settings_fields_html($option){
   $value = get_option( $option['option_name'], '' );
   echo '<input type="text" id="'.$option['option_name'].'" name="'.$option['option_name'].'" value="' . $value . '" />';
}


///Call
<php echo get_option(feedback_email);?>