Foam stabilization by two genetic variants of recombinant αs1-casein
Year: 2026
Type: article
Abstract: Hypothesis The development of recombinant casein with precision fermentation creates an opportunity to use specific genetic variants of casein for the development of foams. Small differences in the amino acid sequence between variants will affect their interfacial, thin film, and foaming properties, allowing for a more targeted design of products. Experiments This study explores these effects in α s1 -casein variant A and B (RCA and RCB), where RCA lacks amino-acid residues 14–26 compared to RCB, which results in a tail-train interfacial configuration after adsorption, whereas RCB assumes a train-loop-train configuration. Air-water interfaces stabilized with both variants were studied with large amplitude oscillatory dilatation and shear, and imaged with AFM. Films stabilized with RCA or RCB were also studied with a thin film balance combined with micro interferometry. Foam properties of both variants were determined using a FoamScan. Findings In thin film balance experiments, low concentrations of RCB (0.05%) formed mobile interfaces that allowed for Gibbs-Marangoni flows and led to superior foam stability (t 1/2 : 1 h). At increased concentrations of RCB the Gibbs-Marangoni flows were inhibited, and foam stability decreased. RCA formed a stiffer, less mobile interface (dilatation and shear) and therefore inhibited the Gibbs-Marangoni flows altogether, which led to low foam stability which improved with increasing concentration (t 1/2 : 8–20 min). Clearly, the deletion of amino acids in caseins can greatly impact their interfacial and foaming behavior. These results highlight the potential for using different genetic variants of recombinant caseins for tuning its functionality.
Language: English
Topic: Proteins in Food Systems
Subfield: Food Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,470
Award: Animal-free milk proteins
OpenAlex ID: W7129410337