Ligation of pork skin gelatin with glucose moieties affects the junction zones in gelled networks

This study aims to investigate the role of the ligation of steric moieties on the formation of junction zones during network formation of gelatin gels. The molecular conformational propensities, heat stability and mechanical properties of gradually chemically modified pork skin gelatin have been evaluated. To this end, glucose moieties are ligated to lysine residues on the protein using the Maillard reaction. It is shown that ligation of small sugar moieties only marginally impairs with triple helix formation and does not interfere with the mechanism of network formation. The Young's modulus (gel stiffness) and the fracture properties decrease with increasing degree of modification, but not the ability to reversibly store energy in the network. It is suggested that Maillardation affects the strand-strand interaction energy, but not necessarily the number of junction zones. A retained recoverable energy while the fracture properties can be affected allows industry to tailor food products in terms of their expected sensory performance.