Transglutaminase is affectionately called “meat glue”. It is sold to Chefs under the trade name Activa™. There may be other brands out there. It was discovered back in 1959 as a component of the blood clotting complement. A common example of culinary use is to bind a bacon wrap to another protein (steak, salmon, etc). Another example seen was to bind salmon tips (leftover from fillets) wrapped in a tilapia filet. Using transglutaminase, proteins will bind in refrigeration and hold after cooking.
None. Is it safe? Yes. This enzyme is GRAS (generally recognized as safe) and has been used for more than 10 years in meats and poultry. For foodservice a “glued” meat product is considered non-intact.
This product would not be considered a “special process”. It would not require HACCP or a food safety plan under the US FDA model Food Code. However, it is noted above that cooking of these foods must be done to the comminuted or ground temperature for red meats of 155°F or above. Poultry would be 165°F or above. The full strength enzyme preparation is not toxic. Therefore, there is little concern for storing the raw chemical in a foodservice environment. This product would require consumer disclosure on a label, but not a menu. It is not a known allergen.
More: USDA Food Safety “Answers” | Federal Register Notice of GRAS | Ajinomoto Sell Sheet