Contribution of κ-/ι-carrageenan on the gelling properties of shrimp myofibrillar protein and their interaction mechanism exploration

BACKGROUND: The contribution and mechanism of kappa-/iota-carrageenan (CG) with different hydration characteristics on the gelling properties of shrimp myofibrillar protein (MP) gelation was studied. RESULTS: The gel strength, water-holding capacity and viscoelastic properties of MP gels were significantly enhanced by 1.0% kappa-/iota (P < 0.05), but the microstructure showed that excessive carrageenan caused fragmentation of the gel network and a corresponding decrease in gel properties. Compared to MP-iota CG, MP-kappa CG showed larger breaking force and shorter breaking distance, thus enhancing the hardness and brittleness of the gel, which might be ascribed to a reinforced network skeleton and a tighter binding of kappa CG-myosin. However, MP-iota CG stabilized more moisture in the gel network, thereby improving the tenderness of the gel, which might be related to the electrostatic repulsion observed between the sulfate groups of iota CG and the myosin observed by molecular docking. In addition, the beta-sheet content and intermolecular interactions might be positively correlated with gel properties. CONCLUSION: In this study, a composite gel system was constructed based on the interaction of MP and CG. The quality differences of two kinds of CG-MP gels were clarified, which will provide guidance for the application of different kinds of carrageenan and the development of recombinant meat products with specific quality. (C) 2022 Society of Chemical Industry.