Chemical modification of gelatin by a natural phenolic cross-linker, tannic acid

Xiaoqing Zhang, My Dieu Do, Philip Casey, Adrian Sulistio, Greg Qiao, Leif Lundin, Peter Lillford, Shantha Kosaraju

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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.

Original languageEnglish
Pages (from-to)6809-6815
Number of pages7
JournalJournal of Agricultural and Food Chemistry
Issue number11
Publication statusPublished - 9 Jun 2010
Externally publishedYes


  • Gelatin
  • Mechanical properties
  • Natural phenolic cross-linking
  • Tannic acid

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