Abstract
Upon heating at 100°C, microbial transglutaminase (MTG) suppressed coagulation of whey protein concentrate (WPC) solution, decreasing solubility and increasing viscosity, particularly with addition of 30 units of MTG. Creep testing of the gel prepared by treating freeze-dried WPC with 10 units of MTG showed that the WPC gels decreased in instant elasticity E0 and that the ratio of Newtonian viscosity, ηN, for E0 increased. WPC gels treated with MTG increased their water-holding capacity. In MTG treatment of WPC solution, low crosslinkage was observed at high concentration and at low pH. These observations are assumed to be due to the molecular structure of the WPC. It is suggested that heat tolerance is conferred on the WPC with treatment by MTG, and that this property seems to arise due to crosslinking between α-lactalbumin and β-lactoglobulin, two main milk proteins.
