PSF-R30

Surficial whey protein deposits under shear

The effect of shear stress on the accumulation of whey protein deposits at a liquid/solid interface is linked to their unfolding and aggregation. Understanding these phenomena is essential to deal with critical and costly industrial issues occurring at the bulk solution/surface interface, such as the formation of a fouling layer during heat treatment and or concentration by evaporation.

The effect of heating on the structural modification of whey proteins is well known. However, the effect of shear is not elucidated: not only there is no consensus on the deposit formation mechanisms but also the experiments were not designed to discriminate the individual effect of shear.

Whey protein solutions were sheared in a rheometer equipped with a plate/plate geometry at a temperature lower than that of denaturation. Both qualitative and quantitative analyses of surficial deposits were conducted by microscopic techniques. Based on their size and morphology, we hypothesized three stages of deposit growth: i) adsorption of initiation points on the surface, ii) their chemical bonding leading to primary deposits, and iii) formation of thicker branched structures resulting from interconnection of primary deposits, and involving non-chemical interactions, much influenced by increasing shear.

Deposit mechanism

Schematic representation of the 3 stages proposed for the whey protein deposit growth

Comparing the stability of whey proteins in the bulk solution and on the surface would help would provide a better understanding of the kinetics of deposit development understand the kinetics of deposit development.

Collaborations

  • Francis Gouttefangeas and Loïc Joanny for scanning electron microscopy (CMEBA)
  • Louis Thomas for atomic force microscopy (PCMP)

Read more

Grostete M., Lee J., Msibi Z., Boissel F., Jimenez M., Jeantet R., Lanotte L. (2024) Exploring the formation of surficial whey protein deposits under shear stress by rheofluidic approach, International Journal of Biological Macromolecules, 274, 133291. https://doi.org/10.1016/j.ijbiomac.2024.133291

Contacts

Luca Lanotte . Scientifique à l'UMR-STLO