BACKGROUND The novel thermo-reversible hydrogels that undergo gelation in feedback to external stimuli have numerous applications in the food, biomedical, and functional materials fields. Muscle myofibrillar protein (MP) has long been known for thermally irreversible gelation. Once the reversible gelation of MP is achieved, its research and application scope will be expanded. 

RESULTS For the first time, this work realized a thermo-reversible MP gelation through elaborate deamidation using protein-glutaminase (PG). The protein concentration and PG reaction time within a window of 1.0−2.5% and 8 h or 12 h were observed to be vital for creating thermo-reversible gels. The gel strength increased with protein concentration. The gel displayed a perforated lamellar microstructure which resulted in high water holding capacity. The rheological results revealed the thermo-reversibility of the gel was robust for up to 5 cycles of heating-cooling. The thermally reversible gelation is closely related to the reversible assembly between individual α-helix and helical coiled-coil. Hydrophobic interactions were proved to be predominantly involved in the formation and stabilization the gel network structure. 

CONCLUSION This work opens up the research scope of the thermo-responsive behavior of MP-based gel, which can foster advances in innovatively wide applications of muscle proteins as well as PG as a novel ingredient in the food industry.

Please see the findings at https://onlinelibrary.wiley.com/doi/10.1002/jsfa.12287.