摘要：The solubility and the selectivity of $\alpha _{\rm S1}$-, $\beta$- and $\kappa$-casein isolation from an industrially produced spray-dried sodium caseinate as a function of temperature (20–40 °C) and of ethanol volume fraction (0–0.6) at pH 5.0–7.5 were studied. Reverse-phase high-performance liquid chromatography and nitrogen balance were used as analytical methods. At 20 °C, casein solubility as a function of pH (5–7) and of the ethanol volume fraction (0–0.6) is quite well represented by an equation describing the ionisation process. $\alpha_{\rm S1}$-, $\beta$- and $\kappa$-casein solubility and $\beta$- and $\kappa$-casein extraction selectivity decrease both with a rise in the ethanol volume fraction to 0.45–0.50 and with temperature increase. For $\alpha _{\rm S1}$-casein, the selectivity increases to 67% for an ethanol volume fraction of 0.47 at 29 °C. This fraction could be used as an emulsifying agent or for cream liqueur production or further purification.
