isolation, purification and some chemical properties of casein from local goats and cows milk

ABSTRACT

Goats and cows alpha[s]-casein were initially purified by fractionation with urea. While, the final purification was done on DEAE-Cellulose. The behavior of these two proteins was similar on the column of ion exchange. The molecular weight of goats and cows proteins were 28846 and 25409 Dalton respectively, while, the isoelectric points of these proteins were 4.5 and 4.2 respectively. The carbohydrate content of goats and cows alpha[s]-casein were 8.47 and 4.37 mg/g respectively, while, their phosphorus content were 17.66 and 9.57 mg/g respectively.Ammo acid analysis of the two pure proteins showed that goats alpha[s]-casein had lower acidic and higher basic amino acids than that of cows alpha[s]- casein, glutamic acidwas the highest concentration in the two proteins, however, no significant differences was noted between these two proteins in acidic and hydrophobic amino acids