Speed up response time of application that uses web services - php

Question

We have a small application that uses the Facebook API to retrieve the posts of an user that is logged with facebook and translate them using Bing Translate API.
When you first login the server retrieves the first 10 posts, sends them to the Bing Api for translation and then sends them to the user. When the user scrolls to the bottom of the page using AJAX the server retrieves the next 10 posts and sends them to BING for translation and inserts them in the webpage.
The problem is that like this it takes a really long time for posts to load. Is there any way to speed up the process?
Using cache to store the next posts before acctualy being needed and loading them from the cache is an option?
include 'test_translate.php';
function loadFirst($facebook){
$result = $facebook->api('/me/home?fields=from,type,story,message,picture,link,source,name,caption,description&limit=10' , 'GET');
$posts = $result['data'];
parse_str($result['paging']['next']);
?>
class="post_paging">
<?php
$toTranslate = "";
foreach($posts as $post){
$toTranslate.= "<div style=\"background-color:#72b0c9; margin:auto; padding-left:15px; padding-right:15px; padding-top:15px; padding-bottom:15px;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;\">
<p><a target=\"_blank\" href = \"http://www.facebook.com/\"";
$toTranslate.= $post['from']['id']."\">".$post['from']['name']."</a> </p>";
if(isset($post['story']))
$toTranslate .= "<p>" . $post['story'] . "</p>";
if(isset($post['message']))
$toTranslate .= "<p>" . $post['message'] . "</p>";
if(isset($post['picture']))
$toTranslate .= '<a target="_blank" href=' . $post['link'] . '><img src="' . $post['picture'] . '"/></a>';
if(isset($post['name']))
$toTranslate .= "<p>" . $post['name'] . "</p>";
if(isset($post['caption']))
$toTranslate .= "<p>" . $post['caption'] . "</p>";
if(isset($post['description']))
$toTranslate .= "<p>" . $post['description'] . "</p>";
$toTranslate.= "</div></br></br>";
}
$result = translate($toTranslate, 'it');
echo $result;
echo "</div>";
}
?>