Catalyst proper has nothing to do with the database. This sounds like a DBIx::Class problem from some of your vocabulary.
There is nothing particularly special about text stored in blobs in MySQL, I think the only practical difference is there is no associated character set; there shouldn't be any problem getting it. It sounds like your schema -- Result(Source) class for the table -- is improperly defined or you're doing something like ->search({},{columns => [qw/ everything but the blob /]}). Without seeing code, those are just guesses: either the My::Schema::Result::TableName is incomplete or the call is excluding the column somewhere along the way. If you show some code, it would be easier to help.
Sidenote: You could inflate the blob content to an XML object of some sort to make it easier to handle and get to the data/text. That's incredibly handy but a little expensive depending on your use case.