Effect of cation type on the formation, structure and functional properties of enzyme-crosslinked pea protein gels and emulsion gels

Gels and emulsion gels were fabricated from commercial pea protein isolate (CPPI) using transglutaminase (TGase) or TGase and mineral ions (Na + and Ca 2+ ). The effects of the different crosslinking mechanisms on the formation, structure and functional performance of the CPPI gels were evaluated. Both TGase and TGase-Na + /Ca 2+ effectively induced gel formation, with the addition of salt ions significantly enhancing gelation kinetics and final gel strength. Rheological, textural, and microstructural analyses revealed that TGase-Ca 2+ -induced CPPI gels exhibited highest elastic and viscous moduli, whereas TGase-Na + -induced CPPI gels demonstrated the highest hardness and a more uniform network structure. However, the addition of mineral ions reduced the water holding capacity, swelling capacity, and freeze-thaw stability of the gels. CPPI emulsion gels crosslinked with TGase and Na + improved β-carotene stability and bioaccessibility after simulated digestion. These findings highlight the potential of using TGase-Na + crosslinked CPPI gels for developing novel cold-set gels in functional food applications.