Cooking Issues

The International Culinary Center's Tech 'N Stuff Blog

Cooking Issues header image 2

The Trials of Transglutaminase—The Misunderstood Magic of Meat-Glue

May 20th, 2011 · 45 Comments · Uncategorized

by Dave Arnold

Hey folks, this isn't what we are talking about! Meat glue is a food-grade enzyme.... not really a glue.

Transglutaminase (TG) –aka meat glue, the stuff that allows you to bond proteins together –has been taking a pounding in the blogosphere recently and, as a proponent of the enzyme, so have I.  At the risk of preaching to the converted (sorry, loyal readers) I’m setting the record straight.  TG is a great tool used by conscientious cooks to achieve fabulous and fantastic culinary results. It is also natural. Don’t know about meat glue? Read my primer.

In March an Australian TV tabloid show called Today Tonight did an “expose” on meat glue.  Here’s  the lead in:

The industry wide secret butchers don’t want you to know about. Major suppliers have been caught using a special product known as meat glue to stick together scraps of meat to sell as prime cuts. But while this product has been banned overseas, there’s no law prohibiting its use here.

This video has gone somewhat viral over the last month. I encourage you to watch it.  It is horse hockey.

[youtube=http://www.youtube.com/watch?v=ydzIlKJmwV4]

In this video you’ll see some classic bad journalism techniques –like getting a butcher who doesn’t like the idea of meat glue to demonstrate it wearing a face mask. The reporters make some nutty claims.

Claim: Meat glue is an industry wide secret butchers don’t want you to know about. Major suppliers have been caught using a special product known as meat glue to stick together scraps of meat to sell as prime cuts.

Truth: Many of the hundreds of horrified comments are reactions to this allegation that companies are defrauding customers by selling glued together scraps of meat as “prime cuts.”  This phrase has been repeated so often that everyone takes it for fact. The Australian show did not point to even one case of a company committing fraud using meat glue. I searched the internet  looking for a documented case of fraud and was unable to find one.  The segment does show a commercial restructured piece of meat, but they don’t show the label because it could not possibly have been sold as a prime cut. That would, indeed, be fraud (in the US anyway) for which the perpetrator could do jail time.  In the US, any meat that has been glued or restructured must be labeled “formed” or “reformed.” See the FSIS ruling on the subject here (this page really cuts through the crap. Ajinomoto fought to make sure that glued meats are clearly labeled as restructured, but not for altruistic reasons: they wanted to to use TG without being required to add “enzyme” to the ingredient label — which they can, because it is used in minute quantities and is considered a processing aid). Furthermore, TG is only one of many, many methods companies could use to bind meats together and defraud customers if they so chose (such as alginates, carrageenan, salt with tumbling, gelatin, compression).

Restaurants don’t have the same stringent labeling requirements than meat packers do. It would be possible for a disreputable restaurant to TRY to pawn off scraps of meat as whole-muscle cuts.  The restaurant would likely be unsuccessful in the long run because their customers would know (see the next claim). Any restaurant using meat glue to cheat their customers should be shut down –but I have never seen or heard of such a case.  The chefs I know who use meat glue care about their customers and the quality of their food.

Claim: Even an expert can’t tell if meat has been glued. You are getting ripped off without knowing it.

Answer: Anyone that has used meat glue knows this is untrue.  The bonds in a glued piece of meat are clearly visible. The smaller the scraps of meat that are glue together, the more obvious the glue-job. Unless I am trying to produce a special effect –like the mokume-gane fish dish I created a while back, I try to keep the number of glue joints in a piece of meat to a minimum –usually one or two.  Why? Because I’m not using meat glue to rip someone off, but to create a piece of meat that will cook better, more evenly and more consistently. I’m trying to make it better for the diner.

Mokume-Gane fish. Meat-glue special-effect technique.

Claim: Meat Glue has been banned in the EU, and might be made from pig’s or cow’s blood.

Answer: False. Tranglutaminase is being legally used in the EU right now. The TG all the chefs use is produced by a naturally-occurring microbe.  There is a second type of meat glue derived from animal sources (thrombin) that was banned in the EU, but not for safety reasons.  It passed the safety test and was rejected because EU regulators didn’t understand the purpose of it and saw the potential for fraud. God help us if regulators get to choose what makes good food. Safety and preventing fraud: important , and a politician’s job. Telling me what it takes to make good food –stay out. See this article on the ban and Ajinomoto’s response.

Claim: Meat glue is unsafe because of the high bacteria count in meat-glued products.

Answer: This is the only claim with a shred of truth.  The most important information I give chefs in meat glue training is: be aware that using TG can introduce bacteria into the interior of your product. The interior of whole muscle meat is relatively sterile. Most contamination is on the outside.  When we cook a traditional rare steak, the searing kills the bacteria on the outside and we are left with uncooked, but fairly safe, rare-meat at the center.  The danger with TG is that a cook might bond two pieces of meat together and treat them like a whole muscle cut without any further precautions… a serious error. Here are the safety guidelines I follow:

*IMPORTANT*

  • If a meat is going to be thoroughly pasteurized (such as chicken or short ribs, which can’t really be cooked to most consumers’ taste and visual satisfaction until they have been thoroughly pasteurized), meat glue is adding no further risk to normal food preparation.
  • If meat glue is used only on the outside of a large muscle cut (such as gluing chicken-skin to skirt steak or bacon to filet mignon), the outside must be thoroughly seared. The inside is just as safe as an unglued cut.
  • If meat glue is used on a product that cannot be pasteurized (most fish, for example), three things must be true:
    1. You must be willing to serve the product raw.  If you wouldn’t hack off a slice of that meat and eat it, don’t glue it and serve it rare.
    2. You must treat the product as if you were serving it raw — wear gloves, practice scrupulous hygiene.
    3. Here is the trickiest part of all, and one with which I am still grappling: you shouldn’t make your customer assume an extra risk (even if you don’t believe it to be a risk) without their knowledge. I once asked a food scientist why it is OK to serve rare hamburgers and sushi, etc.  He said, as far as he is concerned, consumers ordering those products have enough education to understand that they are assuming certain risks –which makes the risks OK. Therefore, if you serve meat that looks basically raw, then the customer isn’t being exposed to risks they aren’t already assuming, and there is no duty to provide extra warnings. If you are in a steak house and you glue two pieces of meat together that had been cut at the packing plant and possibly exposed to contamination, and you then throw that glued meat on a grill and cook it bloody rare, there is definitely a duty to warn.  It is still OK to cook that way, but the consumer must be aware that they are ordering the equivalent of a rare hamburger (it isn’t really that bad, as I’ll explain below). An interesting case is serving a piece of rare fish that has been butchered in the kitchen, meat-glued with one joint, seared, and sliced in the kitchen. Each serving slice is a potential source of contamination just as grave as the slice that preceded the meat gluing.  Is there an extra risk here that requires warning? Dunno.

The vast majority of the products I meat glue are thoroughly pasteurized with low temperature cooking before I serve them and are entirely safe. For those that aren’t pasteurized you need to assess your bacterial risks. The possibility for contamination increases with:

  • The initial bacteria present on the product when it shows up in your kitchen (called the bacterial load)
  • The cleanliness of your kitchen
  • The amount of time a product is exposed to the environment
  • The temperatures at which your products are stored
  • The amount of surface-area exposed to the environment.

The first four considerations are typical ones –the last one is a kicker.  The reason hamburger is so dangerous is that it has a huge surface area exposed to the potentially contaminating environment of meat grinders, kitchens, hands, etc.  All that contamination is thoroughly mixed into the center of the product.  Hamburger is easy to abuse. A piece of meat that is brought into the kitchen whole and sliced once with a very clean knife on a very clean board has a much lower increase in potential contamination than meat you grind.

Randomness in the Blogosphere:

Some random doozies on meat glue are being bandied about. Here is the real deal.

  • Transglutaminase is not an unholy abomination. It is produced in large quantities by a naturally occurring bacteria. No GMO necessary. Bacterial and yeast fermentation have brought us many of life’s great things: bread, wine, and cheese to name a few. By the way, you have different types of TG in your body right now, as part of the blood clotting pathway, the skin synthesis pathway, etc.  The TG from bacteria is a related enzyme.
  • Meat glue does not contain, nor is it related to, MSG. MSG is the sodium salt of glutamic acid (an amino acid). Meat glue is a mixture of enzymes, maltodextrin, and protein (casein or gelatin).
  • I have found no evidence of meat glue being dangerous when handled properly –and I have read and searched a lot.  I invite feedback on this point.  I have heard anecdotal claims from two (unrelated) cooks who claimed to have gotten a contact dermatitis (rash) from occupational exposure to meat glue.  This seems possible, but I haven’t read anything in the literature.  I always tell people not to inhale the powder (which is common sense), but have never found any record of someone who has inhaled it and been hurt (please forward data to me if you have it).
  • The FSIS limits the use of pure tranglutaminse in meat products to 65 parts per million (except in chicken breast where you may use more).  This number seems to contradict the usage statements for meat glue, which is used at up to 1 percent by weight (usually much, much, less).  In fact, pure TG enzyme represents only a tiny percentage of Activa RM, the meat glue we use.  Activa RM is mostly maltodextrin and casein.  Ajinomoto specifically  formulated Activa RM to add less than 65 ppm of pure enzyme when used at one percent by weight of meat.
  • The relationship between coeliac disease and microbial Transglutaminase (mTG) is still being sorted out.  There is no doubt that extra antibodies to human tissue transglutaminase (tTG) are found in coeliac sufferers. I have seen research that supports that mTG can cause problems for coeliacs, and research that says it doesn’t. I have not found any acute cases of problems had by coeliac sufferers linked to mTG in the literature, but prudence says coelicas should avoid large quantities of TG till the data is in.
  • Excess tTG is found in the tissue of people with horrible diseases like Huntington’s and Alzheimer’s. That doesn’t mean consuming TG causes those diseases any more than drinking water causes pulmonary edema. I personally detest the sort of argument that infers (illogically) that because a product is found alongside or in something horrible, it is horrible.

In conclusion: Glue with caution, but glue with pride!

Tags:

45 Comments so far ↓

  • Patricio Wise

    Great post Dave! About time somebody shed some truth onto this subject…

  • Josh

    The fact that you even call it a “product” should tell you something. You are shilling garbage.

    • davearnold

      I call everything a product –tomatoes, steak, booze, cheese, bread, etc; mainly because they are. The fact that you present no reasoned argument should tell you something. Plus I’m not “shilling” anything. I pay for my TG just like everybody else and receive no payment from Ajinomoto.

    • Joe

      Josh – It’s ridiculous that you are turning this into a personal attack; Everyone in the food industry uses the term product to describe various food items and/or end products. So you are either unfamiliar with the lingo because you have not been exposed to it or you are offended because you feel that dave didn’t pay the animal that that piece of meat came from respect. In the first case – don’t open your mouth when you don’t know what you’re talking about and in the latter case, get off your damn high horse. Seriously grow up.

  • Alex

    I am an Australian and this is not the first time the pillar of credible journalism which is Today Tonight has sensationalised a story with no factual content whatsoever. Usually they keep the best for stories on “deadbeat dads” and “welfare cheats” but occasionally they like to scare the masses with a food story about how everyday foods are actually deadly poisons. Usually the credible witness has their face blacked out and have a suitable title such as “concerned housewife”. You can’t stop these types of media obviously and food is an easy target. Great to have a post like this to email and post to friends instead of getting caught up in circular arguments with drunken friends and taxi drivers.

  • Hank

    Saw you on foodography. You should do more TV. Thanks for all the great posts. Meat glue = unfortunate nickname.

  • Nick

    Ditto Alex.

    I’m sure most countries have some form of tabloid tv journalism, but the fact that it’s an Australian show peddling this bollocks is a little embarrassing.

    Thanks for the smackdown Dave. It needed to be done.

  • Barzelay

    I don’t think “meat glue” is an unfortunate name. It’s apt and descriptive. People just have naive and misguided ideas about what food is and should be (due in part to nonsense like this). We have meat saws, meat mallets, meat tenderizers, and ground meat, so I don’t see why meat glue should be any different. It’s the word “meat,” with another word describing a functional characteristic of the item. Instead of buying into the idea that we need to rebrand things whenever idiots become aware of them, let’s just stick to calling the people idiots and go on using concise and descriptive language.

    If it were called “meat feces,” that would be an unfortunate name.

  • Mark

    Dave, Alex and Nick are spot on. It’s unfortunate that people citing today tonight don’t get a chance to watch it on a regular basis, for if they did they would realise that it is trash of the highest order and pay it no attention whatsoever. It’s one of the many shamefully backward things about our country. Anyway, thanks for your blog and efforts in general, it always makes for an interesting and educational read

  • Joe

    Dave,

    When a friend sent me this video I sent them this response in return:

    Haha! The reason why you need to wear gloves is because the enzyme glues together pieces of protein, so with the natural oils and if some other moisture happened to be on your hand then it could cause you to glue yourself to yourself; the same is true for the masks – inhalation of the enzyme before it is cooked can cause respiratory. The enzyme changes however when if faces heat which is why Activa or transglutaminese is kept in the freezer – after the enzyme spends a bit of time in heat, it starts to die and it’s protein bonding capabilities become null. The reason why meat glued together can be considered a higher risk than a whole muscle (like for example a whole tenderloin) is because meat glued together has more area exposed to environmental bacteria; this concern is pretty invalid if the meat is treated right in the first place… people eat tons of raw and cooked meat with an even greater surface area exposed to bacteria and don’t die – Yes, I’m talking about tartare and ground meat products. This is just the media’s attempts at making a splash about something they don’t know about.

  • schinderhannes

    Howdy Dave,

    I don´t really know the wages for cooks in Australia, but I´d expect that the time it takes to align the fibers of small leftover pieces of meat to form something vaguely resemling a steak is in total more expensive than buying one! LOL

    If at all the “fraud” take place in restaurants where refomed pork meat is not properly declarated and sold as “ham” like in pizza outlets (illegal at least in Germany, don´t know about the US). But can people that don´t even know the difference be cheated? Those that know mostly don´t care about the sloppy wording on the menu.

    If you want to scare the public of dangerous practices with meat, I´d rather go for meat tenderizers, the can hammer bacteria straight to the middle of just about anything!

    • davearnold

      I agree Schinderhannes, good to hear from you. The only person I know decrying the use of mechanical meat tenderizers is Douglas Baldwin, of sous-vide primer fame.

  • Monki Bread :: The Official Kitchenmonki.com Blog

    [...] 2. 7 Best Houseplants for Improving Air Quality (via Ecosalon) 3. The Magic of Meat Glue (via Cooking Issues) 4. Make and Eat: Spaghetti with Crab, Cherry Tomatoes and Basil Recipe 5. 5 Simple Tips for [...]

  • Jacob Burton

    It’s nice to see someone who actually cares to do the honest research set the facts straight. The culinary world is already filled with enough dogma; we really don’t need any more misinformation scaring uneducated consumers.

    Thanks for setting the record straight.

  • Hal

    I’m sorry Dave,

    Your logic and facts will never defeat the forces of stupidity.

  • Russ

    I am completely skeptical, especially learning that the meat industry has been using this for years without the consumer’s knowledge. My wife has gone through many major surgeries including 5 colon, 3 obstructions, rectal and loss of a kidney. She loved McDonalds and Wendy’s chicken nuggets. I use to wonder how they could press the chicken together without it falling apart. She would usually purchase less expensive meats that would taste different. I am sure that you can’t guarantee that meat glue (TG) might have had something to do with it.
    Thanks,
    Russ.

    • davearnold

      Howdy Russ, everyone on the internet says chicken McNuggets uses TG, but there isn’t a single reference from or about McDonalds that confirms it (even obliquely). Chicken McNuggets were introduced in 1980 way before TG was being sold. I’m not saying I know for sure there isn’t TG in the formulation now, but I can guarantee that TG isn’t necessary for a McNugget formula. I don’t think you can guarantee you’ve ever had it in those applications.

  • Casey

    Years ago I worked for a very highly regarded independant steakhouse in Boston that was able to serve expensive meat for less during recession issues by getting in beef rib bones and gluing them to ribeye. filet and sirloin. It shaved a few dollars off peoples dinner but if someone had coeliacs we had to offer them something else. Not a great business practice but it helped the restaurant through a tough time.

    • davearnold

      Hey Casey? Why would you glue a rib bone back on a ribeye? Wouldn’t that incur the cost of buying the boneless rib and the rib bones separately? What was going on with the filet and sirloin? Did the restaurant let the consumer know what was going on?

      • Casey

        Just to be clear, I was not the chef and these decisions were not mine.
        What I was told was that it saved a few dollars a pound when buying prime grade ribeyes to get rib bones and glue them on. They weren’t doing filets and sirloin bone in while I was there but I just looked online and they are now. No they did not tell the customer.
        For many reasons my employment at this restaurant was short lived.

  • Meat Glue Mania and Mayhem | meatblogger.org

    [...] dairy products to alter texture, i.e. make them “thicker.”  A thorough article, “The Trials of Transglutaminase,” explains many of of the misconceptions of TG and touches upon some of the other far-fetched [...]

  • Nicole

    Thanks Dave! What an excellent blog. I had never even heard of meat glue before I read this article. I live in Sydney and I tend to take the stance that if Today Tonight says something is bad/evil/toxic etc than it is probably a good thing.

    Cheers,
    Nicole

  • Jethro

    Good job – it’s always fun to tell skeptics that their body produces transglutaminase on its own. Three cheers for meat glue! While you’re at it, might as well let it be known MSG isn’t some holy abomination either.

  • kitchengrl

    Spot on. By the way, as for the coeliac suffers (and the “gluten intolerant”) – relatively uncommon medical conditions should not dictate the way we cook in a general sense. I find those demands incredibly tiresome. It’s important to provide the information necessary for affected individuals to make the decision whether to eat something, or to put them on notice that a food that is perfectly harmless to most people might not work out so well for them. But the idea that TG is dangerous for everyone because it may be a problem for certain people is total crap and the worst kind of tail-wagging-the-dog.

  • David

    Hey Dave, I am interested in knowing what your process would be on “gluing” together a product that would be cooked low temp over a long period of time, and with a sauce? Ex. using multiple layers of boneless short rib to form a more uniform cut and eventually end up with a “steak cut” like product. Will sauce in the bag effect the bond? And if so how can you fix this?

    • davearnold

      Hello David,
      The sauce will not affect the bond after it has been glued, but you can’t bag unglued pieces with the sauce and expect good results on a consistent basis. The sauce will get in between the pieces of meat and disrupt the bonding process. The steps would be: Cut, glue, bag, let set, unbag, sear-etc, add sauce, re-bag, cook.

  • David

    How About gluing cooked product together?

  • Pepperoni Bill

    From time to time, I have vegetarian friends on FB that post the “dirty little secret” youtube video and expect that it will shatter the world of the meat eater. I never comment with my own words. I just post the URL to this page. You offer a thousand times more information on this subject than any poorly made, 2 minute youtube video. People appreciate information and respect your effort to provide no nonsense information. I most certainly do. Do I use it? NO.. but I only make pizzas. Would I? YES…following safety guidelines that you suggest and if it were to offer my customers a better or enhanced product at a considerable cost savings to them. TG rocks. You and the Hammer rock. Also, tell Nastassia that she is correct. There is no worse Steve Miller arrangement than “Abbra Cadabbra”. There is a goofy one he did many years earlier called “The Last Wombat From Mecca”, but it is actually a pretty cool tune with nice bluesy influences. Thanks my friends. My treadmill is nothing without yall!

  • Jackie

    Thanks for posting this. My friends were freaking out about this in a chat, and I thought I should research it more thoroughly. I’m glad to hear that it’s not really such a big deal. Kind of like the “OMG nuggets are made of melted chicken scraps!” uproar not too long ago.

  • Raymond

    Can you glue duck breasts together, fat to meat. Thinking about forming onto a slab to cure as “duck Bacon”.

    Many thx in advance.

  • david

    wow. the writers of that video need to take journalism 101. Thats some bad journalism if I ever saw it.

  • johanna

    Feel relieved with such a reasonable and logistic explanation about transglutaminase. Thank you, Dave.

Leave a Comment

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>