remove certain words before submitting comment

Hello friends, I have a problem. Does anyone know how to call a function each time a comment is posted? I need to verify that the comment text there are certain words and only then send the comment to the database.

I tried this using a

add_filter (‘comment_text’, array (‘Moderate’, ‘moderarComentarios’));

But it only removes the words before displaying, I want something so I can remove it before you write to the database.

this is my function:

<?php

function moderarComentarios($comment){

$pattern = '/love|test/i';

if(preg_match_all($pattern, $comment, $matches)){

foreach ($matches as $matche) {
$test = str_replace($matche, '***', $comment);
}

return $comment;
}}