Modulation of mechanical and surface hydrophobic properties of food protein films by transglutaminase treatment

The effects of microbial transglutaminase (MTGase) treatment on the mechanical and hydrophobic properties of cast films from various food proteins were investigated. SDS–PAGE analyses confirmed that the MTGase treatment led to the formation of insoluble film network for most of food proteins. This enzymatic treatment significantly (P < 0.05) increased tensile strength (TS) values of cast films of all food proteins by 13–33% (except whey proteins). Meanwhile, the influence on the elongation at break (EB) values was mainly dependent upon the molecular nature of proteins. For most of food proteins, both increases in TS and EB values of films were obtained after the MTGase treatment. Furthermore, the surface hydrophobicity of most of protein films was also significantly improved. These results suggest that the enzymatic treatment by MTGase could be used as an effective technique to improve mechanical and surface hydrophobic properties of protein films.