The reaction of gelatin /gum arabic coacervate gels with glutaraldehyde

Curt Thiesnext term
Polymer Research Section, Materials Research, The National Cash Register Company, Dayton, Ohio 45409, USA
Received 1 September 1972;  accepted 10 October 1972.  Available online 9 July 2004.

Abstract

The consumption of glut by various gelatin/gum arabic (GGA) coacervate gels has been examined over a range of conditions. Both acid- and alkali-precursor gelatins were used to form the coacervates. Glut consumptions by several gelatin gels were also determined. All gels examined consumed 0.3 to 1.6 mmole glut/g gelatin. Acid and alkali GGA gels had similar glut uptakes at 4C. Glut consumption by acid-precursor GGA gels increased significantly with increasing gelation temperature (428C) due to temperature-dependent changes in gel structure. The use of commercial versus redistilled glut had no detectable effect upon glut uptakes. Reaction of a gel with glut caused a high degree of insolubilization as a result of intermolecular crosslink formation. Most treated gels were at least 85 wt% insoluble at 55C in phosphate buffer after 428 days extraction. That fraction of a gel solubilized by the extraction process contained both gelatin and gum arabic. Thus, despite the fact that gum arabic has little tendency to react with glut, it is effectively entrapped in the crosslinked GGA gel structure. Gels with lowest glut uptakes were the most soluble ones. They also were the only ones with solubilities that increased upon treatment with NaHSO3 before the gel fraction extraction process. Insolubilization of GGA gels by glut causes their swelling behavior and composition to become essentially independent of pH. Composition and swelling behavior of uncrosslinked gels vary markedly with pH due to the reversible nature of the intermolecular bridges responsible for gelation.



Journal of Colloid and Interface Science
Volume 44, Issue 1, July 1973, Pages 133-141