3.3. Dilatational amplitude sweeps of b-LG, DH3 and DH6 as
affected by the presence of pectin
For the determination of the linear viscoelastic regime, the
interfacial films after 14 h of adsorption time were exposed to sinusoidal
area oscillations at different amplitudes (DA/
A0 ¼ 0.7e5.6%) with constant frequency (f ¼ 0.01 Hz) according to
(Rühs, Affolter, et al., 2013). The results of this experiment are
presented in Fig. 3 in terms of the interfacial moduli E0 and E00 as a
function of the amplitude DA/A0. When the amplitude of deformation
of the interfacial area exceeds a certain value, the interfacial
tension response is not linear to the area variation any more,
accordingly the interfacial structures may be destroyed and the
interfacial moduli drop dramatically (Wüstneck, Moser, &
Muschiolik, 1999). All pure protein and protein/pectin-solutions