Enhancement of foam stability parallel with foamability of the foam stabilized by sodium caseinate-based complex: Octenyl succinate starch acting a dual role

Interaction among the multiple components play a crucial role in regulating the foam properties. In this work, the relationship among the interaction of sodium caseinate (SC)/tannin acid (TA)/octenyl succinate starch (OSA-Starch), rheological properties, and the resultant foam properties was investigated. The results of the phase diagram show that the complexes formed by SC and OSA-Starch through electrostatic interactions depend on pH changes. At pH 4.0 and 5.0, the OSA-Starch constraints the binding between SC and TA, however, it promotes the formation of soluble complexes at pH 6.0. Meanwhile, the OSA-Starch advance the diffusion of SC-based complex (SC or SC/TA) from the bulk phase to the air/water interface and the rearrangement on the interface due to the depletion mechanism, which improve foamability and maintain admirable foam stability. The shear-thickening properties of the foam stabilized by SC/TA/OSA-Starch contribute to foam stability. Finally, the micro-rheology results show that the TA acts as a bridge to connect the SC and OSA-Starch, forming a viscoelastic film around the bubble and maintaining admirable foam stability. This study provides a theoretical basis for the exciting opportunities of the ternary-component complex in interface-dominated food systems.

Automated summary

The interaction among SC/TA/OSA-Starch and the foam properties was investigated, showing that OSA-Starch can influence the formation of soluble complexes at different pH levels. It was found that OSA-Starch plays a role in promoting foam formation by advancing the diffusion of SC-based complexes to the air/water interface. The shear-thickening properties of the foam stabilized by SC/TA/OSA-Starch contribute to foam stability.