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Enzyme-catalyzed gel formation of gelatin and chitosan: potential for in situ applications

Paper ID Volume ID Publish Year Pages File Format Full-Text
12979 826 2003 11 PDF Available
Title
Enzyme-catalyzed gel formation of gelatin and chitosan: potential for in situ applications
Abstract

We compared the ability of two enzymes to catalyze the formation of gels from solutions of gelatin and chitosan. A microbial transglutaminase, currently under investigation for food applications, was observed to catalyze the formation of strong and permanent gels from gelatin solutions. Chitosan was not required for transglutaminase-catalyzed gel formation, although gel formation was faster, and the resulting gels were stronger if reactions were performed in the presence of this polysaccharide. Consistent with transglutaminase's ability to covalently crosslink proteins, we observed that the transglutaminase-catalyzed gelatin–chitosan gels lost the ability to undergo thermally reversible transitions (i.e. sol–gel transitions) characteristic of gelatin. Mushroom tyrosinase was also observed to catalyze gel formation for gelatin–chitosan blends. In contrast to transglutaminase, tyrosinase-catalyzed reactions did not lead to gel formation unless chitosan was present (i.e. chitosan is required for tyrosinase-catalyzed gel formation). Tyrosinase-catalyzed gelatin–chitosan gels were observed to be considerably weaker than transglutaminase-catalyzed gels. Tyrosinase-catalyzed gels were strengthened by cooling below gelatin's gel-point, which suggests that gelatin's ability to undergo a collagen-like coil-to-helix transition is unaffected by tyrosinase-catalyzed reactions. Further, tyrosinase-catalyzed gelatin–chitosan gels were transient as their strength (i.e. elastic modulus) peaked at about 5 h after which the gels broke spontaneously over the course of 2 days. The strength of both transglutaminase-catalyzed and tyrosinase-catalyzed gels could be adjusted by altering the gelatin and chitosan compositions. Potential applications of these gels for in situ applications are discussed.

Keywords
Chitosan; Gelatin; Gels; In situ gelation; Transglutaminase; Tyrosinase
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Enzyme-catalyzed gel formation of gelatin and chitosan: potential for in situ applications
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 24, Issue 17, August 2003, Pages 2831–2841
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us