top

Modulating Viscoelastic Properties of Physically Cross linked Self-Assembled Gelatin Hydrogels through Optimized Solvent Conditions

Modulating Viscoelastic Properties of Physically Cross linked Self-Assembled Gelatin Hydrogels through Optimized Solvent Conditions

J. Dispers. Sci. Technol. 36, 1349-1356, (2015)

Kadam, K., Pochat-Bohatier C., Sanchez J., El Ghzaoui A.

 

ABSTRACT

In this work, an experimental study was conducted on two different types of gelatin from mammalian sources, type A, derived from acid-cured tissue of porcine skin and type B, from lime-cured tissue of bovine skin. The effect of temperature, pH, and ionic strength on viscoelastic properties of gelatin hydrogels was carried out in order to determine the conformational characteristics and phase transition (sol-gel transition temperatures, Tm – melting temperature and T-g- gelling temperature) behavior. The detailed investigation on gelation behavior of gelatin hydrogels was performed with rheological measurements in the temperature range of 5-35 degrees C as a function of pH with and without added salt (NaCl) and gelation transition temperatures evaluated for all these conditions. Both types of gelatins show polyelectrolyte effect with added NaCl (0.001-0.1 M) for the studied pH conditions (pH 1 or pH 7). The maximum in the gelation properties was observed at lower NaCl concentrations (0.001 M for type-A and 0.01 M for type-B). The significant improvement in gelation behavior with optimum pH or amount of added NaCl imparts longer stability to gelatin hydrogels, which were reflected in degradation study. This work establishes a relationship between gelatin properties and the values of temperatures and solvent conditions (pH and NaCl concentrations), thus providing insight on how to control the stability and melting of gelatin gels in view of their potential application in the biomedical and food industries.