Contact
    Start Publications Transient measurement and structure analysis of ...
    ←  Publication Finder
    KSV NIMA

    Transient measurement and structure analysis of protein-polysaccharide multilayers at fluid interfaces

    Year: 2019

    Journal: Soft Matter, Volume 15, 1-Aug, page 6362–6368

    Authors: Bertsch, Pascal; Thoma, Alexandra; Bergfreund, Jotam; Geue, Thomas; Fischer, Peter

    Organizations: Swiss National Science FoundationSwiss National Science Foundation (SNSF) [200021-137941, 200021-175994]

    The formation of electrostatic protein-polysaccharide multilayers has attracted attention for the design of fluid interfaces with enhanced stability and functionality. However, current techniques are often limited to measuring final multilayer properties. We present an interfacial shear rheology setup with simultaneous subphase exchange, allowing the transient measurement of biopolymer multilayers by their viscoelasticity. The successive and simultaneous adsorption of beta-lactoglobulin (beta-lg) and low-methoxyl pectin were investigated at the n-dodecane/water interface at pH 4. The successive injection of pectin increased the viscoelasticity of an adsorbed beta-lg layer by electrostatic complexation. On the other hand, simultaneous adsorption impeded adsorption kinetics and interfacial layer strength due to complexation in the bulk phase prior to adsorption. Neutron reflectometry at the air-water interface confirmed the formation of an initial beta-lg layer and electrostatic complexation of a secondary pectin layer, which desorbed upon pH-induced charge inversion. The layer formed by simultaneous adsorption mainly consisted of beta-lg. We conclude that protein-polysaccharide complexes show limited surface activity and result in a lower effective protein concentration available for adsorption.
    View publication