Kids eat paste. Why worry about meat glue?

You may have recently seen something on the internet, social media, or the news about something called ‘meat glue.’ What the heck is that?

What the media refers to as ‘meat glue,’ is known in the meat industry as transglutaminase (TG) or beef fibrin. They are enzymes used to bind proteins together. Enzymes are proteins that cause chemical reactions to happen in living things. There are several types of proteins in the body, proteins that hold things together (think tendons), proteins that make things move (muscle), proteins that break down food to produce energy (some of these are enzymes), proteins than break down other proteins (some of these are enzymes used as meat tenderizers), and proteins that help build other proteins to help them function correctly.

TG and fibrin fall into the last category. They help to build other proteins. They cause proteins in muscle to bind with one another to form a strong bond. So in meat, they can help bind two pieces of meat together.

Why is it used in the meat industry?



Beef tenderloin

 Muscles are all kinds of crazy shapes. Some are huge, some are long and skinny, some are shaped like triangles or trapezoids or who knows what. It is hard for butchers to take those muscles with all those different shapes and form them into cuts of meat that are the size and shape that people want to eat. For example, the tenderloin is the most tender muscle in the body and is used to make filet mignon. It is about as big around as a base ball at one end and tapers down to a point at the other. On one end, butchers can cut nice pretty round steaks, but as they cut more and more steaks, they get smaller and smaller. As the butcher gets closer and closer to the small end, the pieces are too small to make a nice steak. They are still the most tender muscle in the body, but they won’t make pretty, portion sized steaks. So, meat scientists and chefs use TG or fibrin to stick two tenderloins together with the skinny end of one adhered to the fatter end of the other one and visa versa. It is still tenderloin, still the most tender cut in the body, but with TG, butchers can cut more, pretty round steaks. More meat for everybody!

Sometimes, chefs use TG or fibrin to get the bacon to stick to filet mignon. I’ve seen examples of it used on salmon and to make that imitation crab stuff.

Where is it found?

If these ingredients are used in a food that you buy at the store, according to USDA, the food must be labeled ‘formed’ or ‘fabricated’ or ‘shaped’, as in ‘Formed Chicken Breast’ or ‘Fabricated Steaks.’ A meat product containing TG or fibrin will also have an “enzyme” to transglutaminase enzyme” in the ingredient list. When you cook them, you should treat them like ground meat and cook them to at least 160°F for red meat and all chicken should be cooked to 165°F. 

Of course, you can’t read ingredient statements when you dine at restaurants. You can always ask. Foods that are prepared prior to coming to the restaurant will have TG on their ingredient list, and a chef will be able to tell you if he or she is using it themselves. They should be trained in preparing foods containing TG safely, so it should be cooked to safe temperatures.

Some people are concerned that TG or fibrin are going to be used to turn cheap cuts of meat into cuts that can be sold at a higher price. Cheap cuts of meat are cheap for a reason; nothing can change the texture or flavor to make them like filet mignon. If a chef or a company were doing something like that, not only would it hurt their business, it would be against the law. The USDA dictates labeling laws on cuts of meat, and only tenderloin can be labeled as ‘tenderloin’. The folks at the American Meat Institute stated that they do not have any evidence that these deceptive practices are happening.

Furthermore, TG is too expensive to be used on cheap cuts of meat. Because of its price, you will only see it used on expensive cuts like tenderloin or salmon patties or in high-end restaurants where chefs demand higher prices. So, you’re not really consuming it very often. AMI estimates that about 8 million pounds of meat containing these products are sold annually, that is out of 49 billion pounds of beef and pork sold each year (0.016%).

As a meat scientist, I think that TG and enzymes like it are neat and exciting. I think it is fun to see what chefs and the guys and girls in research and development come up with using them. I don’t feel like we are trying to trick anyone. And, I know to cook these products to 160°F.

Here are some other good sources on transglutaminase and fibrin.

• This video is the best I’ve seen explaining the process and showing how TG is used.
• In this Meat Myth Crusher video, my friend Dr. Dana Hanson, from North Carolina State University explains how TG is used.
• This is a blog post about meat glue from culinary blog called Cooking Issues.
• This is a blog post from Chris Raines about Meat Glue.
• This is a statement about binding enzymes used in meat products from the American Meat Institute.