CHICAGO (CBS) -- The McRib sandwich recently returned to all McDonald's restaurants and, as is typical when the McRib shows up on the menu, the return of the popular sandwich generated a lot of fanfare.
So what goes into the sandwich that makes it so popular? More than 70 ingredients make up the McRib and, yes, one of them is pork. But as CBS 2's Vince Gerasole reports, there's also an ingredient that can be found in shoes.
The McRib has a cult following, so much so that McDonald's brings it back every now and then at all its restaurants, but what's behind its taste?
"These little guys are not bones. Anything with a rib should probably have a rib bone in it," registered dietician Cassie Vanderwall said.
Vanderwall gave the McRib a closer look and found the McRib has azodicarbonamide, which is used to bleach the flour in bread.
It has other uses.
"It could be on your yoga mat, in your gym shoes, in your anything that's rubbery," Vanderwall said.
That has double meaning as you work out or walk off the McRib's 500 calories and 26 grams of fat.
Then there's the pork – which is really restructured meat product. In other words, it's made from all the less expensive innards and castoffs from the pig.
Asked if it's bad to eat those meat byproducts, Vanderwall said, "No, they're still part of the animal."
Angela Keaveny, founder of Rowdydow BBQ – southern style barbecue that is served at restaurants throughout the city, said, "You want a smokey flavor, you want a tangy flavor."
Unlike the McRib, Keaveny said her barbecue contains "pure pork shoulder, Boston butts, that's the only thing that we make the Rowdydow barbecue with."
Keaveny is an entrepreneur who sticks to natural ingredients like vinegar and anchovies, but she knows mass-marketed foods need some help from food additives.
"There's a whole food science behind it. It's cheaper, faster products," she said.
But sometimes "how does it taste?" is all consumers really want to know.
Even so, Vanderwall said the McRib ingredient list "reminds me of a chemistry lab."
But all those chemical additives in the McRib are recognized by the U.S. Food and Drug Administration as safe to eat, as long as you don't eat a McRib every day for 10 years.
Still, when you hear your bun is made with the same stuff that's in your shoe, it really doesn't sound appetizing.
for more features.