Effects of Amount of Alcohol on the Gelation of Compound Gelatin Solutions

Abstract

A series of measurements was conducted to clarify the mechanism for the sol-gel transition of gelatin in the presence of alcohol (about 1%,3%,5%,10% or 20%) added to the gelatin solution. We examined the rheological and microstructural characteristics, measured the viscosity by a non-destructive method, the optical rotation, dynamic viscoelasticity, rupture characteristics and 17O-NMR data, and observed the microstructure of the gelatin gel samples by scanning electron microscopy. The gelation time, specific rotation, dynamic elasticity and dynamic viscosity of the gelatin solution were each reduced with increasing amount of alcohol. The gel samples of the gelatin solution containing 10% and 20% of alcohol both showed strong ductility. The latter sample with 20% of alcohol contained many vacancies and formed a coarse network structure.