Transglutaminase treatment of pea proteins: Effect on physicochemical and rheological properties of heat-induced protein gels

Rheological properties of heat-induced pea protein isolate (PPI) gels with added microbial transglutaminase (MTGase) were studied under various reaction conditions. A positive linear relationship was observed between level of MTGase used (0 to 0.7% w/w) and shear stress and shear strain of heat-set commercial pea protein isolate (PPIc) gels at 92 °C following incubation at 50 °C. Use of MTGase allowed for preparation of PPIc gels of similar strength and elasticity as commercial soy protein isolate gels and commercial meat bologna. MTGase treatment did not alter thermal properties of PPI gels. The shear stress and strain of PPIc gels were also improved following low temperature (4 °C) incubation of PPI with MTGase. Enhancement of shear strain or gel elasticity of heat-induced PPI gels with MTGase has not been reported before and provides opportunities for extending the properties of pea proteins when developing new food products.