A few years ago I had a student who, unintentionally, made a major cut through the middle of a beef tenderloin while trimming it. We used what we could and shaped medallions from it but we lost a fair amount. I joked about it and said it would be a great test for " meat glue". Then last year my TA at the time, Carlos, brought in a sample of a Japanese product, Activa. Activa is a product made by the Ajinomoto corporation that is a protein binder enzyme transglutaminase. Transglutaminase is a naturally occuring enzyme that is created by a frementation process. Glutamin is the major amino acid that is found in muscle tissue. It is considered a non-essential amino acid due to the fact that the body creates it so it doesn't need to be consumed but many body building supplements contain it due to its abilty to promote muscle strength. It is also used for digestive health and is an essential energy source for the intestinal lining. Glutamin is used for many treatments medically and its attributes are still being discovered.
Transglutiminases are a number of enzymes that bond proteins. The transglutaminase found in the blood stream forms a fibrin bond when an injury occurs, initiating clotting. The Ajinomoto Co creates this type of enzyme by using a fermentation process and, once isolated, mixing it with a delivery powder that can either be mixed with water or sprinkled over meats. MEAT GLUE! It physically binds raw meat proteins together.
In class we have used it to bind a variety of meat items. Certainly it can be used to repair cuts made in error but it can also be used to dramatically increase yields on certain cuts. We used it to bind tenderloin sections to minimize tail and tip trim. We also took two boneless lamb loins and joined them to create a larger circular medallion. It worked really well for stuffing items. Boneless chicken breasts can be stuffed and rolled and will hold without any string or toothpicks used. It will bind any type of animal protein but will not hold fat well.
Recently we had to fabricate 725 portions of tenderloin medallions for a graduation celebration. We used PSMO tenderloins and we averaged almost 12 - 6 oz steaks per tenderloin which is a really good yield. I made a slurry of Activa and glued the tail sections and head sections together to create a much more uniform medallion. We wrapped them in plastic and let them set overnight. The only issues were when we attempted to mix tenderloins that were slightly different colors. You could see the different sections which looked odd but once seared you could not tell. Activa basically creates a bond that is undetectable and is basically like a new meat.
There are three basic formulations of Activa and the difference between them is the type of protein you are trying to bind. We used Activa TG- FP which is meant for leaner raw meat proteins such as beef or pork. The other two types, Activa TG- RM and TG- RI, have different uses. RM is used for either seafood, poultry or processed meats. RI is used to bind protein for milk products such as yogurt and cheese.
The companie's site is not very high tech http://www.activatg.com/ but it explains the product well. Carlos got them to send a sample by simply requesting it. It is available commercially and is relatively expensive about $100 for a kilo ( 2.5 lbs) but a little goes a long way. I used about 1/4 lb for 725 medallions which more than made up for its cost in yield savings.
Here are the basic steps we used for