Effects of gelatin-polyphenol and gelatin-genipin cross-linking on the structure of gelatin hydrogels

The effects of two cross-linking agents (genipin and polyphenol) on the physical properties of gelatin hydrogels were studied to determine the more effective natural cross-linking agent. The highest gel strength obtained with polyphenols was 136.9N/mm(2) at concentrations up to 360g polyphenols/g gelatin, whereas the highest strength of samples cross-linked with genipin was 98.4N/mm(2) with 300mg genipin/g dry gelatin. Scanning electron microscopy showed that gelatin modified by polyphenols at 360g/g gelatin had the most compact surface. Cross-linked gelatin-polyphenol exhibited a markedly enhanced denaturation temperature and greater thermal stability than gelatin-genipin.