QforCAS – Quest for casein structure - the importance of calcium and phosphate nanoclusters to the structure and function of casein micelles

Dairy proteins are highly functional and will be increasingly in demand for their high-quality performance in foods. However, processes such as concentration, membrane filtration, drying etc. can change the physico-chemical properties of the casein micelle, ultimately affecting the functional properties of the casein-based end-products. Therefore, it is important to clearly understand the changes occurring to these proteins during processing. QforCAS aims at combining the advanced structural analyses developed in earlier studies, to study the native and modified structure of the casein micelle, thereby creating a robust understanding of the internal structure of the casein micelle structure.

By: Anne Lau Heckmann

There is an increased demand from industry and consumers for highly tailored and value-added ingredients from dairy. The creation of novel casein ingredients has become increasingly feasible with the advent of filtration technologies, as it is now possible to separate caseins from whey proteins, by controlling membrane pore size, and by changing diafiltration medium or environmental parameters (pH, temperature). It may also be possible to manipulate the casein ingredient’s structure and functionality and hence these changes could result in high value ingredients. 

In the past years, through projects such as FILTRATE and DE NOVO, the project team has learned how to probe the casein structure changes in unprecedented detail, through a combination of X-ray scattering and detailed chemistry composition. QforCAS will use this advanced toolbox to link processing to the structural changes to be able to predict future performance of the casein-based ingredients. The goal is to fully understand the role of calcium phosphate nanoclusters in the structure of the native casein micelles (CM) and then relate this to modified structures of the CMs and their function. The project will focus on the effect of temperature, pH, phosphorylation degree (by treatment with a phosphatase), β-casein enrichment of the CM and concentration. The CMs stability to heat and their gelation behavior in relation to their structural modifications will also be studied.