shows storage module (G0) as function of strain amplitude
for formulation 1. For those samples with added stabilizer (Fig. 5a),
two different regions were observed linear viscoelastic region
where G0 was constant and nonlinear region in which G0 started to
decrease with increasing strain. Within the linear viscoelastic
region, the G0 values were independent of the applied strain
meaning that the samples behaved like a viscoelastic solid (Fig. 5a).
The length of the linear section is closely related to product stability
since it is thought to account for the formation of physical
entanglements between proteins and carbohydrates at the
oil/water interface providing structure to the liquid (Franco et al.,
1995). Increasing the homogenization pressure resulted in higher
values of G0 when compared with the control sample, meaning that
HPH increased the strength of the network. This was evidenced
both by the increased magnitude of G0 plus extended linear range
indicated by the critical strain which is determined as 85% of G0 at
the linear range. The highest strength of the network judging by the
magnitude of G0 values was obtained at 45 ± 3 MPa/92 C and the
application of higher homogenization pressures (78e286 MPa) did
not increase the strength of the network (Fig. 5a). The yielding
point or critical strain is associated with the breakdown of the
secondary network of particles and it marks the transition from
viscoelastic solid to viscoelastic liquid (Hesarinejad et al., 2014). In
the case of samples without added stabilizer, the G0 values as
function of strain amplitude were too low and rather scattered
regardless of the HPH conditions. Magnitude of the G0 for products
without stabilizer was one logarithmic scale lower. The linear
ranges were not as easily visible due to the detection limits of the
instrument; although, some exhibited better linear ranges.