Whey protein directed in vitro vaterite biomineralization: Influence of external parameters on phase transformation

Biomineralization produces elegant structures that are evident naturally in the form of physical anatomy of various organisms. This process is governed by proteins and organic molecules that regulate the entire mechanism leading to the formation of biominerals. In this study, we have used whey protein, one of the two major components of milk protein to direct the in vitro CaCO3 biomineralization. Whey protein has dictated the selective formation of vaterite, the least stable among the three crystalline phases of CaCO3. It was easily recovered and readily available to be reused. The study was extended to understand the influence of the change in conditions such as the concentration of the whey protein, sequence of addition, temperature, pH and ionic strength of the solution on phase transformation and to justify the role of whey protein in assisting the formation of the vaterite particles.