Big Ben -- Fired By Jerky Company

Ben Roethlisberger has just lost a major sponsor -- after his beef jerky company decided that the sexual assault investigation left a bad taste in the mouths of the consumers.

TMZ spoke with the people behind Big Ben's Beef Jerky, who tell us they've officially cut ties with the Pittsburgh Steelers QB -- which means production has been halted and all remaining product is to be "destroyed."

The jerky was produced by a company called PLB Sports -- the same group behind Doug Flutie's famous "Flutie Flakes" cereal. According to Ty Ballou -- president of PLB -- the company decided Ben was no Flutie ... and enforced the "morality clause" in Ben's contract.