Structural and rheology properties of pea protein isolate-stabilised emulsion gel: Effect of crosslinking with transglutaminase

The microstructures and characteristics (water holding capacity (WHC) and rheological properties) of pea protein isolate (PPI) emulsion gels produced via transglutaminase (TGase) with different oil-weight fractions (phi, 20%similar to 50%) were studied in the present work. The results showed that the WHC and gel strength (storage modulus) of PPI emulsion gel were raised with increasing of phi. Simultaneously, the proteins entrapped within the network gradually increase due to the enzymatic treatment, which resulted in a tighter internal structure of emulsion gel. At high oil-weight fractions (e.g. 50%), the network of the emulsion was essentially a coarse chain of particulate, mainly forming a 'close-knit' oil droplet. Therefore, the gelation mechanism is related to the state of proteins in the system, which are divided into proteins adsorbed and unadsorbed on the interface. The results will be of significant assistance in comprehending the theories of the gelation process and the protein emulsion gels immobilisation by the enzyme.