Self-Assembly of Rice Bran Globulin Fibrils in Electrostatic Screening: Nanostructure and Gels

Abstract EN

The effects of various ionic strengths and protein concentrations on the fibrils structure and gel properties of rice bran globulin (RBG) at pH 2.0 were investigated using atomic force microscopy (AFM), rheometer, and scanning electron microscope (SEM).

AFM images showed the morphology of assembling RBG fibrils from strand beads to becoming branch clustered, when electrostatic repulsive forces attenuated gradually with increasing ionic strength.

NaCl seems to accelerate the kinetics of fibrils formation, resulting in a significant increase in Th T fluorescence intensity.

The increased ionic strengths promote particle size increasing and zeta potential decreasing synchronously.

The percolation model G ' ~ C - C p n be used to calculate theoretical RBG gels concentration at various ionic strengths (0–500 mM), which decreased from 15.17 ± 0.63 to 2.26 ± 0.27 wt%.

SEM images exhibited a granular mesh-like gel structure.

A more homogenous structure occurred in low ionic strength.

This study elucidates properties of RBG fibrils and gels as a bioactive material.