Casein micelle formation as a calcium phosphate phase separation process: Preparation of artificial casein micelles through vacuum evaporation and membrane processes

Abstract

Industrial-scale production of artificial casein micelles (ACM) is required to produce dairy alternatives from recombinant casein. However, the currently common micelle preparation method of dropwise mixing casein and salt solutions is inefficient and may prove difficult to scale up. Here, we view casein micelle formation as a process driven by calcium phosphate phase separation in the presence of casein. On this basis, we developed novel routes to prepare ACM through vacuum evaporation, forward osmosis, or reverse osmosis. ACM prepared through these methods have similar properties and improved coagulation behaviour compared to those prepared through the currently common method and natural bovine casein micelles. The properties and functionality of the micelles depend on the preparation time and surface area available for micelle formation, with longer times and larger surfaces (i.e. lower fluxes) yielding smaller ACM that form firmer curds. These novel processes enable fast, efficient, and continuous production of ACM for application in future dairy alternatives.