title: Chemical modification of gelatin by a natural phenolic cross-linker, tannic acid.
abstract: Chemical modification of gelatin by a natural phenolic compound tannic acid (TA) at pH 8 was studied, and the properties of the modified gelatin materials were examined. The cross-linking effect was predominant when the TA content was lower, resulting in the formation of a partially insoluble cross-link network. The cross-linking structure was stable even under boiling, and the protein matrix became rigid, whereas the mechanical properties were enhanced. An effective cross-linking effect on gelatin matrix was achieved when the amount of TA was around 3 wt %. Further increase in the TA content enhanced the grafting and branching reactions between gelatin and TA in conjunction with the hydrogen bonding between gelatin and TA molecules. These effects produced an increase in molecular mobility of gelatin matrix, and the materials displayed a behavior similar to that of plasticized protein materials.
authors.affiliation: CSIRO Materials Science and Engineering, Private Bag 33, Clayton South MDC, Clayton South, Victoria 3169, Australia. Xiaoqing.Zhang@csiro.au
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Zhang
authors.forename: My Dieu
authors.initials: MD
authors.lastname: Do
authors.forename: Philip
authors.initials: P
authors.lastname: Casey
authors.forename: Adrian
authors.initials: A
authors.lastname: Sulistio
authors.forename: Greg G
authors.initials: GG
authors.lastname: Qiao
authors.forename: Leif
authors.initials: L
authors.lastname: Lundin
authors.forename: Peter
authors.initials: P
authors.lastname: Lillford
authors.forename: Shantha
authors.initials: S
authors.lastname: Kosaraju
mesh_terms: D055598:Chemical Phenomena; D003432:Cross-Linking Reagents / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D019800:Phenol / Q000737:chemistry; D013634:Tannins / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D013634:Tannins; D019800:Phenol; D005780:Gelatin