Acylation and Solubility of Casein Precipitated by Carbon Dioxide

ABSTRACT: Casein precipitated from milk using carbon dioxide (CO 2 ‐casein) and calcium caseinate were acetylated and succinylated. Aqueous solubility of casein was measured at pH 3, 5, 7, and 9. Acetylation extent was lower for CO 2 ‐casein while both succinylated to similar extents. Solubility between the unmodified caseins was similar except at pH 5 with CO 2 ‐casein being less soluble. Succinylation enhanced solubility for both caseins at pH 5, 7, and 9 with similar solubility between the succinylated caseins at each pH. Acetylation enhanced solubility at pH 5, however CO 2 ‐casein still possessed lower solubility than calcium caseinate. Acylation and solubility behavior indicated structural features in CO 2 ‐casein which were not present in calcium caseinate.