Application of transglutaminase for food processing

Abstract

This chapter discusses the experiments conducted for food processing by the application of Transglutaminase (TG), which is an enzyme that catalyzes the acyl-transfer reaction between the γ-carboxyamide group of glutamine residues in peptide-bonds and primary amines. The most effective reaction to be used for the food industry is the cross-linking of protein molecules. The cross-linking reaction may be found in both intermolecular and intramolecular proteins. TG is widely distributed in nature and has been found in various animal tissues, fish, plants, and microorganisms. Mass production by the fermentation method and in commercialization of TG has been achieved for the first time in the world. This microbial transglutaminase (MTG) has various effects on the physical properties of food proteins. MTG has been put to practical use for meat and seafood processing, surimi products, noodles and pasta, and tofu. Crosslinks, G-L bonds, which are caused during MTG reaction are covalent bonds that are stable unlike electrostatic and hydrophobic interactions. Therefore, even after the retort treatment, foods treated with MTG can maintain its original texture better than non-treatment ones. The breaking strength of the retorted sausage decreases by 20% as compared to the non-retorted sausage. Also, the texture of noodles and pasta is improved by the MTG treatment. Noodles with MTG can maintain its texture even after acid- or heat-treatment for longer shelf life. With the addition of MTG, texture of various noodles, such as the Chinese noodle, Udon, Soba, and pasta, are improved. Lastly, Tofu gel treated with MTG has good consistency and improved smooth texture.