Influence of Cross‐Linking by Microbial Transglutaminase on Physicochemical Properties of Eggshell Membrane Collagen

Collagen from eggshell membrane (EM) was stabilized via a cross‐linking procedure using microbial transglutaminase as an alternative, nontoxic cross‐linking reagent for its low stability and low mechanical strength. The physicochemical features of collagen solutions (5 mg/mL), which were cross‐linked by different concentrations of MTG (30, 40, 50, 60, and 70 U/g collagen), were examined. The SDS‐PAGE, differential scanning calorimetry (DSC), residual amino group content, scanning electron microscopy (SEM), and viscosity of solutions were evaluated. The results revealed that applying higher concentrations of MTG in cross‐linked collagen solutions leads to an increase of about 32°C–39°C in denaturation temperatures ( T d ) and a 75.76% decrease in residual amino group content. The simultaneous effect of different temperatures and concentrations of MTG on viscosity illustrated an improvement of approximately 30 Pa·s in the viscosity of cross‐linked collagen at 50°C. The enzymatically cross‐linked porous structures displayed finer microstructure with interlinked micron‐sized pores, exhibiting a 74% reduction in size compared to the uncross‐linked collagen. These results suggest that combining MTG and EM as sources of collagen represents an innovative potential route for the safe cross‐linking of collagen‐based matrices. This innovation could have practical applications in reducing waste EM, which is a by‐product of egg breaking in industrial and domestic settings, and utilize them to produce firmness and stabilize collagen.