I had never noticed this until I opened a tin of Dominican Glory maduro. I hate ketchup, and was overwhelmed by the smell. I couldn't stand to smell the tobak, so I just loaded it up and smoked. Thankfully the tobak did not taste anything like that smell. I am going to let that tin rest for awhile, and then revisit.
P.S. It was a great tobak, being that I smoked cigars before getting into pipes.