title: Alternative reaction mechanism for the cross-linking of gelatin with glutaraldehyde.
abstract: FT-IR, in combination with residual amino group determination using a fluorescence technique, has been used to investigate the chemical functional groups involved in the cross-linking reaction between glutaraldehyde and gelatin molecules. The results suggest that, at high pH values (i.e., close to the pK(a) of lysine), the cross-linking reaction is mainly governed by the well-known Schiff base formation, whereas at low pH (i.e., when the amino groups of lysine are protonated), the reaction may also involve the -OH groups of hydroxyproline and hydroxylysine, leading to the formation of hemiacetals.
authors.affiliation: Department of Food Science and Microbiology, University of Milan, Via Celoria 2, 20133 Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Farris
authors.forename: Jianhui
authors.initials: J
authors.lastname: Song
authors.forename: Qingrong
authors.initials: Q
authors.lastname: Huang
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics
chemical_list: D003432:Cross-Linking Reagents; D005780:Gelatin; D005976:Glutaral