Enzymatic synthesis of chitosan–gelatin antimicrobial copolymer and its characterisation

BACKGROUND: Schiff bases can be formed by reaction between acylamino and the amino group with microbial transglutaminase (MTGase) as catalyst and used in protein crosslinking in the food industry. A novel chitosan–gelatin copolymer for coating meat products can be synthesised using MTGase as catalyst, with the characteristics of both chitosan and gelatin. The aim of the present study was to synthesise and characterise chitosan–gelatin antimicrobial copolymer. RESULTS: The yield of copolymer increased with increasing gelatin/chitosan ratio, while bacteriostasis of Staphylococcus aureus by the copolymer decreased, showing that its bacteriostatic ability depended on the amino group in chitosan. Under optimal synthesis conditions of 50 °C, pH 6 and 40 min reaction time the copolymer yield was 64.5% at a gelatin/chitosan ratio of 0.6. Bacteriostasis of S. aureus by 10 g kg−1 copolymer solution was 70% of that by chitosan. CONCLUSION: A novel biological dressing frame material with excellent biocompatibility and antibacterial properties has been successfully prepared. The results of this study provide a background for further investigation of potential applications of chitosan–gelatin copolymer in the areas of agriculture and food. Copyright © 2009 Society of Chemical Industry