Transglutaminase

What is Transglutaminase?

Transglutaminase is a naturally occurring enzyme found in plants, animals, and bacteria. It catalyzes cross linking reactions between wheat and other proteins.

In weak gluten or gluten-free systems it is used to increase volume and improve the structure of bread. In frozen dough, it increases dough stability and protects it from damage.

Origin

Transglutaminase (TG) was first identified about 50 years ago. At that time, TG for food applications was not widely used because it was expensive, difficult to refine, and required calcium to work.

In 1989, researchers at the Japanese company Ajinomoto discovered a strain of soil bacteria, Streptoverticillium mobaraense, which produced large quantities of easily purified transglutaminase. Besides being easy to produce, this microbial TG does not require calcium and is very easy to use.¹

Function

Transglutaminase can function as a dough conditioner and can overcome the deficiencies in the quality of wheat gluten used in breadmaking. It is an enzyme alternative to chemical oxidizing agents and catalyzes cross-linking bonds both within protein molecules and between molecules of different proteins.

Besides improving the baking quality of wheat flour, it enhances the rheological properties of the dough by stabilizing pore size and elasticity. Other benefits of TG-ase include its positive impact on the sensory properties of bread, texture and loaf volume.

Commercial Production

There are several different forms of transglutaminase. For baking applications, TG enzyme is obtained using biotechnological techniques.

The selected strain of microorganism is nurtured and fed in a seed fermenter until it is multiplied thousands of times. After the seed fermentation, cells are transferred to a larger tank where fermentation time, temperature, pH and air are optimized for growth.  When fermentation is complete, the broth (mixture of cells, nutrients and enzymes) is filtered, purified and dried. In order to avoid oxidation, TG should be stored in vacuum packaging and under refrigeration.

Application

Favorable dough conditions for catalytic activity of transglutaminase include a temperature of 40 °C and pH 5.5.²

Applications and effects of transglutaminase (from Improve your Dough Improver):³

FDA Regulations

Under specific circumstances, enzymes can be considered processing aids and will not need to be declared on the label. None-the-less, enzymes used in baking must be safe. Transglutaminase preparations from S. mobaraensis for protein crosslinking in cereal products are considered GRAS substances.⁴

Examples of products where TG can be used with corresponding concentrations include:

• Pasta products at 25 parts per million (ppm)
• Bread products at 15 ppm
• Pastry products (cakes, pies, doughnuts, etc.) at 20 ppm
• Ready-to-eat cereal products at 45 ppm
• Pizza dough at 20 ppm
• Grain mixtures (burritos, tacos, etc.) at 25 ppm

References

1. Zhang,D. Zhu, Y. Chen, J. “Microbial Transglutaminase Production: Understanding the Mechanism”, Biotechnology and Genetic Engineering Reviews, 26:1, 2009. Pp 205-222, DOI: 10.5661/bger-26-205
2. Kieliszek, M. Misiewicz, A. “Microbial transglutaminase and its application in the food industry. A review”  Folia microbiologica. 59,3. 2013.  241-50.
3. Esteller, M. “Improve Your Dough Improver with Transglutaminase Enzyme.” BAKERpedia. https://bakerpedia.com/improve-dough-improver-with-transglutaminase-enzyme/
4. Rulis, A. Agency Response Letter GRAS Notice No. GRN 000055. CFSAN/Office of Premarket Approval. 2001. wayback.archive-it.org/7993/20171031025001/https://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/NoticeInventory/ucm153744.htm. Accessed 20 March 2019.