brookcove
Posted : 12/4/2008 1:50:59 AM
The gizzard is actually an organ called the ventriculum. It's a digestive organ - it's a very strong muscular stomach chamber with a hard coating on the inside to protect the tissue from the hard material the bird swallows ("grit";). The muscles of the gizzard then grind that grit around (wow, very alliterative) and break up the hard coatings of seeds and the chitinous shells of insects, that the birds eat. Birds don't have teeth so this is their substitute for chewing, essentially.
The short answer is, it's mostly muscle and therefore is at least as nutritious as breast meat. Maybe more since the stomach is the one of the only chicken parts that get worked in today's confinement raising farms!