Food foams such as marshmallow, Chantilly and mousses have behavior and stability directly connected
with their microstructure, bubble size distribution and interfacial properties. A high interfacial tension
inherent to air/liquid foams interfaces affects its stability, and thus it has a direct impact on processing,
storage and product handling. In this work, the interactions of egg albumin with various types of
polysaccharides were investigated by drop tensiometry, interfacial rheology and foam stability. The
progressive addition of egg albumin and polysaccharide in water induced a drop of the air–water surface
tension which was dependent on the pH and polysaccharide type. At pH 4, that is below the isoeletric
point of egg albumen (pI ¼ 4.5) the surface tension was decreased from 70 mN/m to 42 mN/m by the
presence of the protein, and from 70 mN/m to 43 mN/m, 40 mN/m and 38 mN/m by subsequent addition
of xanthan, guar gum and k-carrageenan, respectively. At pH 7.5 the surface tension was decreased from
70 mN/m to 43 mN/m by the simultaneous presence of the protein and k-carrageenan. However, a higher
surface tension of 48 and 50 mN/m was found when xanthan and guar gum were added, respectively,
when compared with carrageenan addition. The main role on the stabilization of protein–polysaccharide
stabilized interfaces was identified on the elasticity of the interface. Foam stability experiments
confirmed that egg-albumin/k-carrageenan at pH below the protein isoeletric point are the most efficient
systems to stabilize air/water interfaces. These results clearly indicate that protein–polysaccharide
coacervation at the air/water interface is an efficient process to increase foam stability
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