Properties of β‑Lactoglobulin Aggregates and Gels as Affected by Ternary Emulsifier Mixtures of Tween 20, Lecithin, and Sucrose Palmitate

The influence of sucrose palmitate,
Tween 20, and lecithin on the
properties of heat-induced aggregates and cold-set gels of β-lactoglobulin
was studied based on an experimental mixture design with a fixed total
emulsifier concentration. Emulsifiers were added to the protein solution
before heating. Aggregate size and absolute values of ζ potential
increased with the addition of emulsifiers, among which lecithin had
the most pronounced effect. The water retention of the aggregates
correlated positively with the aggregate size. Gels had reduced fracture
stress and strains with increasing sucrose palmitate and decreasing
Tween 20 contents. The fracture properties correlated with the ζ
potentials of the aggregates, and larger aggregates led to gels with
higher water-holding capacities. The emulsifiers hence influenced
the gel properties indirectly via the aggregate properties. The impact
of emulsifiers on food structures should therefore be considered when
a food product is designed.