Grasping an innovative process to form microparticles from whey proteins

The process of forming microparticles from the major whey protein, β-lactoglobulin, consists of a first liquid step where the solution of b-lactoglobulin with traces of lactose (or sucrose) is adjusted at pH 9.5 and stored at 4°C for up to 6h. Then the solution is then freeze-dried and the resultant powder is dry-heated at 100°C for up to 12h.

The dry-heated powder, containing the newly formed particles, is then dissolved in water for use or analysis.

To form microparticles:

• Alkaline pH is only required during the liquid step,
• It allows the shift of native dimers of b-lactoglobulin to monomeric species and the formation of b-lactoglobulin aggregates by intermolecular disulphide bridges. These aggregates are probably precursors of the final microparticles,
• Lactose is only required during the drying step,
• A reducing sugar, such as lactose in this case, is necessary and the Maillard reaction during dry heating is essential,
• Dry-heating produces covalent bonds other than disulphide bonds. We assume that bifunctional compounds such as dicarbonyl produced by the Maillard reaction are involved in these bonds.

Scheme of mechanisms for the formation of microparticles showing b-lactoglobulin aggregation in solution and protein crosslinking by bifunctional compounds during dry heating. A picture of microparticles observed by confocal laser scanning microscopy is shown  (500 × 500 µm²)

The present research opens avenues to design protein microparticles from various sources of whey or from specific mixtures of whey proteins involving the β-lactoglobulin.

Read more

Famelart M.H., Sevrin T., Schong, E., Rousseau F., Hamon P., Pezennec P., Croguennec T., Bouhallab S., Lee J., 2026. Dry heating-induced microparticles of β‑lactoglobulin: understanding the respective role of alkaline pH and lactose, ACS Food Science & Technology. 10.1021/acsfoodscitech.5c01081

Famelart M.H., Croguennec T., Sevrin T., 2021. Optimisation of microparticle formation by dry heating of whey proteins. Journal of Food Engineering. 10.1016/j.jfoodeng.2020.110221

Schong, E., Famelart M.H., 2019. Influence of casein on the formation of whey protein microparticles obtained by dry heating at an alkaline pH. Food Research Int. 10.1016/j.foodres.2019.04.001

Schong, E., Famelart M.H., 2019. Influence of lactose on the formation of whey protein microparticles obtained by dry heating at alkaline pH. Food Hydrocolloids. 10.1016/j.foodhyd.2018.08.018

Famelart M.H., Schong E., Croguennec T., 2018. Dry heating a freeze-dried whey protein powder: Formation of microparticles at pH 9.5. Journal of Food Engineering. DOI 10.1016/j.jfoodeng.2017.12.010

Schong, E., Famelart M.H., 2018. Dry heating of whey proteins leads to formation of microspheres with useful functional properties. Food Research International. 10.1016/j.foodres.2018.07.004

Schong E., Famelart M.H., 2017. Dry heating of whey proteins. Food Research International. DOI 10.1016/j.foodres.2017.08.057

Financial support

This study was supported by the Interregional project PROFIL managed by the BBA Industrial Association and funded by Regional councils of Brittany (grant N°13008651) and Pays de la Loire (grant n°2014-07081).

Contact

Florence Rousseau

Jeehyun Lee