Pilot-scale β-casein depletion from micellar casein via cold microfiltration in the diafiltration mode

The aim of this study was to produce pilot scale batches of β-casein concentrate and micellar casein concentrate with reduced β-casein level. The isolation of β-casein was done using membrane filtration at cold temperatures (≤5 °C). A micellar casein concentrate was obtained from skim milk by means of warm microfiltration (MF) at 50 °C (0.1 μm pore size, ceramic membranes). The concentrate was stored at 2–3 °C for approximately 40 h to induce temperature-dependent dissociation of β-casein from casein micelles. β-casein was separated from the cold-stored concentrate using MF (0.3 μm pore size, organic membranes) at ≤5 °C. β-Casein permeate was warmed up to 50 °C to lead self-association of β-casein micelles before ultrafiltration at 50 °C (10 kDa cut-off, organic membranes). Two streams, a β-casein-depleted and a β-casein concentrate, were generated. A purity of 92.64% and a yield of up to 18.07% were achieved for β-casein.