While several companies and research teams have now developed animal-free caseins using precision fermentation, an important part of the process has previously been missing.
To be used in products such as cheese alternatives, caseins need to undergo a process called phosphorylation, where phosphate groups are added to them. This allows the caseins to bind to calcium compounds, forming particles called micelles.
Previous attempts to achieve the phosphorylation of animal-free caseins have been unsuccessful, but in a new study from the Technical University of Denmark, researchers have successfully produced phosphorylated caseins in Escherichia coli bacteria. An alternative phosphomimetic strategy has also been developed by substituting serine residues with aspartate to mimic phosphorylation.
“Transformative breakthrough”
The properties of the resulting caseins were found to be comparable to bovine caseins in terms of calcium-binding affinity, digestibility, and structural integrity. The phosphomimetic casein is said to be a simpler system, while the phosphorylated casein more closely resembles bovine casein.
According to the researchers, precision fermentation-based caseins could play a pivotal role in the development of alternative proteins and the transformation of the food system. However, they note that further research is required to scale up animal-free casein production and integrate the ingredient into end products.
“The ability to produce phosphorylated recombinant caseins represents a transformative breakthrough in the alternative protein industry, addressing the longstanding challenge of achieving phosphorylation at native sites, a key barrier to commercialization,” says the study. “By refining phosphorylation strategies, this work lays the foundation for producing functional recombinant caseins.”
