abstract
The aim of this study was to evaluate the effect of electrostatic interaction between egg white protein
(EW) and pectin in a high sugar content system (80 wt% total solid) on the foaming properties (density,
overrun and stability) and foam rheological properties. A central composite rotatable design was carried
out to study the effects of biopolymer concentration (1.40e5.60%, w/w) and EW:pectin ratio (7:1e63:1)
on the apparent viscosity before whipping, foaming capacity (density and overrun) and foam rheological
properties (storage modulus G’, loss modulus G” and phase angle d) of sugar/EW/pectin mixtures at pH
3.0. The apparent viscosity increased as biopolymer concentration increased while EW:pectin ratio had
no significant effect (p>0.10) on this response. At 7:1 EW:pectin ratio, the mixture presented low foaming
capacity, resulting in foam with less solid character and low stability, possibly due to the pectin excess in
the system. At 49:1 EW:pectin ratio, the mixture showed higher foaming capacity and foam elasticity.
The formation of soluble complexes between EW and pectin possibly increased the continuous phase
viscosity and enhanced the foam stability by slowing liquid drainage.
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