Nearly continual food contamination cases have people questioning and looking askance at additives in food. Which in general is a good thing. But one of the things that seems to be getting slammed and scaring people is Transglutaminase, which is better known to chefs, and now the public, as “Meat Glue.” Yeah, probably not the best name for a product ever. But we are fans. We even sell it in our store.
What is it?
Transglutaminase, or meat glue, is a naturally occurring enzyme found in plants, animals, bacteria, and yes, people. It arrives in kitchens in a powder form.
What does it do?
Meat glue bonds protein molecules together with a super strong —covalent— bond by linking two amino acids: glutamine and lysine. So it allows you to connect pieces of proteins to each other to form a single larger piece.
And why would we want to do that exactly?
The most common use of meat glue in the kitchen is to restructure or reform cuts of meat. With meat glue you can take the perfectly good scraps from trimming a filet and craft a new medallion of meat, thereby limiting kitchen wastage and saving in food costs.
Or it is used to make a cut like a tenderloin more uniform. A tenderloin at one end is large and round but tapers to a wide, flat end. If you take two tenderloins, lay them together top to tail and stick them together with meat glue, you have a more uniform shape, which means a more uniform cooking time. And more matching, pretty-on-the-plate, customer pleasing pieces of meat when you slice.
Meat glue is also used in more creative ways in more molecular kitchens like Wylie Dufresne's where he uses it to fuse different proteins together, like fusing bacon to cod medallions, or to make shrimp noodles, or casing-free sausages. At the Fat Duck Heston Blumenthal once made a “mackerel invertebrate” by de-boning a fish and gluing it back together.
(Less glamorous uses? it's a key part of making chicken nuggets, deli meats and faux crab.)
So it's not at all dangerous?
The main issues food safety folks have with meat glue is that techniques that use meat glue usually mean more handling of the meat which in itself offers up more chances for contamination.
Also, when a meat is reassembled or reformed, basically part of the outside surface is becoming the middle, increasing the chance of contamination. Restructured meats should be cooked to a higher temperature that a natural piece. Good clean kitchen practices and proper cooking technique make it safe.