Web Release Date: October 19,
Enzyme-Catalyzed Phase Transition of Alginate Gels and Gelatin-Alginate Interpenetrated Networks

Laboratoire ERRMECe UFR Sciences et Techniques Université de Cergy-Pontoise, 2 avenue Adolphe Chauvin BP222- 95302 Pontoise cedex, France
Received April 3, 2007

Abstract:
The enzyme-catalyzed gel-sol transition of calcium-alginate obtained by internal gelling strategy with the help of an entrapped alginate lyase is described. We show that alginate molecules and enzyme-produced oligoalginates shorten the gel time of physical gelatin gels (5% and 1.5%), probably due to local protein concentration increase. Interpenetrated networks composed of calcium-alginate and of gelatin were obtained only if elongation of gelatin helices inside a pre-existing calcium-alginate network could occur and only for low gelatin concentration (1.5%). The physical gelatin network is almost reversible inside the alginate one. Both networks can be obtained in the presence of alginate lyase, but gel-sol transition of calcium-alginate cannot be obtained in the presence of gelatin.
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