Topological rearrangements and surface rheology: a multi-scale approach on dairy proteins foams - Institut Agro Rennes-Angers Accéder directement au contenu
Communication Dans Un Congrès Année : 2018

Topological rearrangements and surface rheology: a multi-scale approach on dairy proteins foams

Résumé

The main destabilisation processes in aqueous foams are liquid drainage, coalescence and disproportionation. Due to their amphiphilic nature, proteins can reduce surface tension ϒ, increase liquid phase viscosity and form a visco-elastic interfacial film surrounding the gas bubbles. A correlation is believed to exist between surface rheology of the protein interfacial film and foam stability. Indeed, surface rheology on protein films helps the understanding of foam stability. Two kinds of surface deformation may be applied on a single planar protein film, shearing and expansion/compression (or dilatation). The dilatational elasticity modulus must be larger than 2ϒ to prevent disproportionation. A higher surface shear viscosity is correlated with a better stability against drainage. More generally, higher surface shearing modulus improved stability. However, full understanding still is a challenge because of foam complexity. Foams have confined interstices and spontaneous dynamic rearrangements happen, which cannot be reproduced using only single planar interfaces. Thus, the goal of this work is to bring a multi-scale approach by combining dynamical T1 topological rearrangements of protein films to interfacial rheology measurements.T1 rearrangements occur spontaneously during a foam lifetime or as it flows inside a pipe for example. For small-molecular-weight surfactants, their kinetics have been shown to be an important parameter for the foam stability. In the present work, we aimed at studying the relationship between the rheology of protein interfacial films and the kinetics of T1 rearrangements in protein foams.Two dairy commercial products were studied, sodium caseinate and whey protein isolate (WPI). They differ by their molecular structure and surface rheological properties. Purified β-Lactoglobulin, the main protein in WPI, has also been evaluated. Links between T1, surface rheology and foaming properties will be discussed.
AERC le bon pdf.pdf (1.63 Mo) Télécharger le fichier
Format : Présentation

Dates et versions

hal-01780800 , version 1 (27-04-2018)

Identifiants

  • HAL Id : hal-01780800 , version 1
  • PRODINRA : 427740

Citer

Alexia Audebert, Stéphane Pezennec, Sylvie Beaufils, Valérie Lechevalier-Datin, Cécile Le Floch-Fouéré, et al.. Topological rearrangements and surface rheology: a multi-scale approach on dairy proteins foams. Annual European Rheology Conference 2018 (AERC 2018), Apr 2018, Sorrente, Italy. ⟨hal-01780800⟩
115 Consultations
25 Téléchargements

Partager

Gmail Facebook X LinkedIn More