Design and characterization of casein-whey protein suspensions via the pH-temperature-route for application in extrusion-based 3D-Printing

The current interest in individualized food through additive manufacturing has identified a need for more information on the formulation and printability of potential ingredients. Here, the effect of formulation parameters of casein-whey protein suspensions like the pH (4.8-5.4) as well as the casein content (8.0-12.0% (w/w)) mixed with whey protein (2.0-3.0% (w/w)) and the effect of pre-processing parameters including the denaturation of whey proteins (80 degrees C, 10 min; adjusted pH 6.55, 6.9 and 7.1) on the gel formation via the pH-temperature (T)-route was studied. Rheological measurements showed that the sol-gel transition temperature (G' = 1 Pa) decreased and the aggregation rate of the casein-whey protein suspensions increased with increasing heating pH value. The aggregation rate was considered to be a key parameter predicting the printability of formulations. By exceeding a certain aggregation rate (250 Pa/10 K), casein-whey protein suspensions were found to be printable resulting in firm and stable gels.