Thermo-responsive behavior of glycerol-plasticized oleogels stabilized by zein
Shaghayegh Keshanidokht, Saket Kumar, Peter W. Thulstrup, Matías A. Via, Mathias P. Clausen, Jens Risbo
Abstract
A series of zein-stabilized oleogels were prepared and plasticized by the addition of glycerol. The rheological and microstructural properties of oleogels were studied as a function of glycerol and zein concentration. The plasticized zein oleogel was best characterized as gels with a weak-link regime. The fractal dimension calculation as an indication of structure density indicated that oleogels at low glycerol content had a loose protein network that became denser with further addition of glycerol. Increasing zein concentration formed a denser oleogel network. The oleogels showed a thermo-responsive rheological property in the range of 25–100 °C that was reversible based on glycerol/zein ratios. The transition from solid-like to liquid-like behavior of oleogels by heating started from 75 °C, where G′ could drop up to two orders of magnitude. Besides, the structural analysis did not show any indication of protein secondary structural denaturation during heating.