Beamline setup
Deposits of casein micelles

How deposits of casein micelles form and redisperse

During the skim milk filtration, casein micelles accumulate at the membrane surface and form a cohesive and compressible gel, which reduces the filtration performance. Studying the properties of casein micelle deposit, i.e. its structure and reversibility, is thus of crucial significance. This was the aim of Floriane Doudiès’ PhD.

To study the gel properties, we developed two complementary strategies:

  • in-situ, by small angle X-ray scattering (SAXS), to observe micelle concentration profiles at the surface of the membrane and thus to follow the gel formation and re-dispersion of casein micelles during the filtration;
  • ex-situ, to evaluate the compressibility of the deposit by studying rheological and cohesive properties of concentrated micelle dispersions.

 We demonstrated that:

  • At 7°C the micelles are less compressible, their sol-gel transition concentration is lower and they develop more cohesive interactions than at 20°C;
  • During filtration, releasing the applied pressure partially removes the casein micelle deposits due to decompression and re-dispersion of micelles. Casein micelle compression is less reversible at 12°C than at 42°C.

 

Soleil and Floriane

The filtration deposit is microscopic (thickness <10–4 m), and equipment required for its study is colossal: Floriane Doudiès, during the analysis of the deposit at the Beamline SWING of the synchrotron SOLEIL

 

 

 

 

 

This work opens the way for the quantitative characterization of the reversibility of membrane fouling based on the physicochemical properties of the filtration deposit.

Collaborations

The PhD thesis of Floriane Doudiès was co-financed by the French National Research Institute for Agriculture, Food and Environment (INRAE) and the Brittany Regional Council.

Read more

Doudiès, F., Arsène, A.-S., Garnier-Lambrouin, F, Famelart, M.-H., Bouchoux, A., Pignon, F., Gésan-Guiziou, G., 2019. Major role of voluminosity in the compressibility and sol–gel transition of casein micelle dispersions concentrated at 7°C and 20°C. Foods, 8 (12), 652. DOI: 10.3390/foods8120652

Doudiès, F., Loginov, M., Hengl, N., Karrouch, M., Leconte, N., Garnier-Lambrouin, F., Pérez, J., Pignon,F., Gésan-Guiziou, G., 2021. Build-up and relaxation of membrane fouling deposits produced during crossflow ultrafiltration of casein micelle dispersions at 12°C and 42°C probed by in situ SAXS. Journal of Membrane Science, 618, 118700. DOI: 10.1016/j.memsci.2020.118700

Loginov, M., Doudiès, F., Hengl, N., Karrouch, M., Leconte, N., Garnier-Lambrouin, F, Pérez, J., Pignon, F., Gésan-Guiziou, G., 2021. On the reversibility of membrane fouling by deposits produced during crossflow ultrafiltration of casein micelle suspensions. Journal of Membrane Science, 630, 119289. DOI: 10.1016/j.memsci.2021.119289

Contacts

Geneviève Gésan-Guiziou • Leader of the Membrane Processing team/UMR STLO