Transglutaminase (Activa) Troubleshooting

[David Sundstrom]

Got started late in this game, I suppose, but at now I can stand on the shoulders of those who've come before me.

So I humbly ask for some basic advice. Perhaps this thread could become one about basic troubleshooting.

I purchased some Activa RM from Modernist Pantry. It sat unopened on the countertop for a couple of weeks before I gave it a try. I had a nice large rectangular flank steak. I cut it in half, patted it dry, and then dusted both sides with the Activa. I thought I had it covered pretty well, not caked on, but covered. I put the two halves together, vacuum sealed, and put it in the fridge between a couple sheet pans with milk jugs on top for weight.

When I took it out the next day (>12 hours) I noticed that while the two pieces were stuck, you could clearly see the seam and you could work it loose without a lot of effort and start pulling it apart. I grilled the meat, and then cut it into steaks across the grain. You could see where the two halves pulled apart in places as the meat contracted during cooking.

I thought Activa would glue this meat into one consolidated mass. It kept the two pieces together for cooking, but didn't create the illusion of an unnaturally thick flank steak.

So what went wrong? Was my Activa bad? Does it degrade that quickly even when unopened? (btw, I vacuum sealed and froze the remainder in the deep freeze). Does flank steak have too coarse a grain? Do I need to dust more aggressively or make a slurry?

I'd love to do more with it, but if it is unstable and degrades too quickly (as some people have written) it won't be too practical in a home environment.

[Broken English]

Activa should be stored in the freezer, even the one you're using, store it in a sealed container.

The grey seam is normal, you have to really use as little as possible to avoid having a thick, grey line through the meat. Using a fine tea sieve works well

As for the bonding, I find it works better if you cook the product while under vacuum, as the glue works faster at a higher temperature, so it's perfect for sous vide where the vacuum helps retain the shape.

At work we were using it to create a ballotine of the belly pieces of cod, and while it looked great, the glue stopped the natural flakiness of the fish and gave it a composite texture, which I wasn't a fan of.

Hope this is of some help.

[Broken English]

I should add I've never used the slurry technique, so the grey streak may be avoided by using this method. I'm not sure.

[mkayahara]

I should add I've never used the slurry technique, so the grey streak may be avoided by using this method. I'm not sure.

Generally speaking, Activa RM isn't intended for slurry applications, because it's got sodium caseinate in the mixture, which will bond to itself. According to Ideas in Food, an RM slurry has a working time limit of about 20-30 minutes.

Seeing a seam where the meat was bonded isn't uncommon, especially if the Activa is applied relatively thickly. Your best approach is to dust it generously and evenly, then pick up the meat and dust off the excess. This isn't a case of "more is better"; you want to use as little as possible (but as much as necessary).

[Chris Hennes]

It should also be noted that even with perfect Activa application, close inspection will show that you've still got two pieces of meat, and you will be able to tell when you bite through it and the muscle structure changes. It's useful for approximating "the illusion of an unnaturally thick flank steak" but it's just an approximation.

[olicollett]

Hopefully this should be of help

http://www.cookingissues.com/primers/transglutaminase-aka-meat-glue/

[IndyRob]

Generally speaking, Activa RM isn't intended for slurry applications, because it's got sodium caseinate in the mixture, which will bond to itself.

I received my first delivery of Activa RM last week and, before I read this, I used it in a slurry in my eagerness to perform my first experiment. It seemed to work fine.

I can't really comment on the color of the transitional layer as I was bonding pork fat to lean porn loin. That transition is already a pretty dramatic one. But I don't recall seeing any gray layer.