Kraft Parmesan cheese contains 3.8% wood pulp.  Which is why you should be able to buy it at Home Depot. Other brands are higher.

The FDA sent a letter to a Pennsylvania cheese maker saying "Your Parmesan cheese products do not contain any Parmesan cheese" Instead, Castle Cheese Inc. was cramming its Parmesan cheese with lower-quality substitutes like Swiss, mozzarella, white cheddar AND cellulose (a filler made out of wood pulp that's legal in small amounts), then they distribute it to grocery chains nationwide. Bloomberg tested samples from many supermarkets and found lots of Parmesan cheese suffered from the same issue.

Tthe Wisconsin Center for Dairy Research says cellulose is permitted as a cheese filler as long as it doesn't exceed 4% of the final product, but a Walmart grated Parmesan came in at 7.8% cellulose, while a Jewel-Osco version was at 8.8%. And a Whole Foods brand whose label didn't indicate any cellulose tested at 0.3%.

Cheese makers are doing this for the money. One VP says competitors with sub-par products often underbid him by up to 30%.

They eat that loss, you eat bad cheese. Of course, you might be able to use it as underlayment….