Ya lo consegui y creo que ya funciona bien:
Código PHP:
public function deleteBookFromSearch($idBook){
$index = $this->indexBaseDir.DIRECTORY_SEPARATOR.'book-index';
if (!file_exists($index)){
return 0;
}
$hadle = Zend_Search_Lucene::open($index);
//$this->openIndex($index);
$query = "idBook:$idBook";
$hits = $hadle->find($query);
$num = 0;
foreach ($hits as $hit){
$hadle->delete($hit->idBook-1);
$hadle->commit();
$num++;
}
return $num;
}