How does cheese manufacture begin?

Two forms of cations (mainly Ca and Mg) are present in the micelle, as bound to caseins by mainly phosphoserine groups (Pser-Ca) or as a precipitated salt together with phosphate called CCP (colloidal calcium phosphate for Ca). These 2 forms were changed at the lab scale, the fine composition of micelles was measured and modelled using a software called Milk salts GLM.

We concluded that:

• The content in bound cations affects the gel firmness, by changing the surface charge of the casein micelles and their ability to establish bonds;
• The content in precipitated CCP is negatively correlated to the dynamic properties of the casein micelles, i.e. its ability to rearrange during gel firming and during whey drainage after cutting the gel

Gel structure observed by confocal fluorescence microcopy with model milk containing:

The gel with depleted micelles has larger pores, with consequences on the gel ability to rearrange and on gel firmness.

• Control (CTRL) casein micelles (1)
• CCP-depleted (CCP-D) casein micelles (2)
• CCP-enriched (CCP-E) casein micelles (3)

This work suggests that knowing the fine mineral composition of casein micelles allows to predict the properties of the cheese gels and their drainage behaviour.

Collaborations

This work was carried out during Julien Bauland’s PhD and was funded by Chr-Hansen SAS and the ANRT.

Read more

Bauland, J.; Famelart M.H.; Faiveley M.; Croguennec T. (2022). Rheological properties of enzymatic milk gel: Effect of ion partitioning in casein micelles, Food Hydrocolloids, 130, 107739 https://doi.org/10.1016/j.foodhyd.2022.107739

Contacts

Thomas Croguennec . Scientifique à l'UMR-STLO