The physico-chemical and functional properties, appearance and microstructure were determined of industrially – produced sodium caseinate, calcium caseinate and potassium caseinate obtained by extrusion – cooking. The sodium caseinate and potassium caseinate were characterised porous microstructure and the highest values for water solubility (89,8-90%), water and fat absorption capacity (4,05-4,67 g water/1 g of preparation), and emulsifying capacity (87-90,3%). Calcium caseinate showed compact, packed microstructure and the lowest values for water solubility (84,2%), water (1,39 g water/ 1 g of preparation) and fat absorption (320 g oil/100 g of protein) and emulsification yield (84,2%). The microstructure of caseinates was found to be very important factor determining the functional properties of caseinates.