Dairy Proteins .Casein Proteins 80%of milk proteins a-casein β-casein K-casein isoelectric pH 4.6 Whey Proteins 20%of milk proteins B-lactoglobulin a-lactalbumin isoelectic pH 5.5 Casein Proteins Hydrophilic and hydropobic amino acids largely segregated in primary structure Large amounts of proline Serine phosphate in a and B casein located in hydrophilic section of protein H HO一CH2 -COOH NHz 20P0CH2 -COOH a&B Casein Protein Structure Hydrophilic Hydrophobic amino acids amino acids 77 Dairy Proteins • Casein Proteins 80% of milk proteins α-casein β-casein κ-casein isoelectric pH 4.6 • Whey Proteins 20% of milk proteins β-lactoglobulin α-lactalbumin isoelectic pH 5.5 Casein Proteins • Hydrophilic and hydropobic amino acids largely segregated in primary structure • Large amounts of proline • Serine phosphate in α and β casein located in hydrophilic section of protein CH2 COOH NH2 H C -2O3PO CH2 COOH NH2 H HO C α & β Casein Protein Structure Hydrophilic amino acids Hydrophobic amino acids O PO3 = O = 3 PO