Gelation of Commercial Pea Protein Isolate: Effect of Microbial Transglutaminase and Thermal Processing

In the studied commercial pea protein isolate (PPI) some physicochemical modifications are induced in the protein structure during its processing. That fact would result into a reduction of proteins techno-functional properties. It has been evidenced by Differential Scanning Calorimetry the protein denaturation what gives as a result poor gelling ability. Microbial transglutaminase (MTGase) was added at different concentrations to improve the gelation process at two different settings/thermal treatments to make suitable texture PPI gels as a base for various meat and/or seafood analogues. SDS-PAGE analysis indicated that MTGase activity was focused on the polymerization of vicilins and legumins resulting in the promotion of new intermolecular protein complexes (increase in beta-sheet aggregates). Rheological data showed that at 23% PPI with 5 and 7 U/g protein of MTGase the gel strength increased in terms of breaking force and complex modulus. It also improved the conformational stability and flexibility of their gel networks. The results suggest that appropriate gels with 23% PPI could be obtained adding 5 U/g MTGase able to be used as meat and/or seafood analogues.