Thank you fanteamgear.
I have access to the database, but decided to further explore how AbanteCart was getting the value of "meta_description", in order to not create additional database connection and query for a single field.
As in "product_description", AbanteCart was able to extract the value "meta_description", I searched for that string.
The missing part, was adding "$this->document->setBlurb($product_info['blurb']);" in product.tpl.
I edited my original post, so that everyone can benefit from the procedure.
Cheers.