Rheological properties of gellan gels containing filler particles

Abstract

Influences of rigid (glass) and deformable (gellan) particles dispersed in gellan gels were studied to better understand the effect of structure on the rheological properties of model composite foods. Composites with inclusions at 0%, 10%, 20%, and 30% volume fractions (VF) were tested under small deformation oscillatory shear. In gels containing rigid particles, the dynamic shear storage modulus (G′) decreased initially, exhibited a minimum around 20% VF, then increased at 30% VF behavior that was attributed to physical interactions among particles. In gels containing deformable particles, the linear decrease in G′ with increasing VF may be due to particle compliance under stress or to particle separation from the matrix, thereby causing gel weakening.