2.6 Microrheological characterization
The microrheological properties were determined with reference to a
previous method (Mengjie et al., 2021). The microrheological properties
of walnut butter were investigated using a microrheometer (Rheolaser
Master, France). The freshly prepared walnut butter was placed in a 4 mL
cylindrical glass tube to observe the Brownian Motion of the particles.
The setting time was 4 h, and the temperature was 25°C. The changes in
the mean square displacement (MSD) curve, the elasticity index (EI),
solid-liquid balance index (SLB), and the flow index (FI) of the sample
particles were recorded using Rheosoft Master software 1.4.0.0 software.
The elasticity index (EI), solid-liquid balance index (SLB), and the
flow index (FI) were obtained from the mean square displacement (MSD)
curves. EI was the inverse of the height value of the plateau zone in
the MSD curve. SLB was the slope value of the elastic plateau zone of
the MSD curve. FI was the inverse of the characteristic decorrelation
time corresponding to the decorrelation time required to reach the
correlated scatter plot (Fernandes and Salas Mellado, 2018).