PHYSICAL PROPERTIES AND CHEMICAL COMPOSITIONS OF PASTEURIZED COW MILK MARKETED IN ADDIS ABABA, ETHIOPIA

Abstract

Milk represents an important intake in a typical diet due its high nutrient and mineral content. Consequently, milk must be of satisfactory quality in order to protect the health of the community. This study investigated Physical Properties and Chemical Compositions of Pasteurized Cow Milk Marketed in Addis Ababa, Ethiopian. Seven locally available pasteurized cow’s milk samples were collected and codes were given. Physical Properties and Chemical Compositions were determined following standard methods of analysis. The mean values of pH, moisture, total solids, total ash and titratable acidity were in the range of 5.81–6.42, 84.78 91.91%, 8.09–15.16%, 0.546–0.739%, and 0.228–0.411%, respectively for the seven pasteurized milk samples. The determination of minerals in pasteurized cow’s milk samples were carried out after optimization of the digestion of milk, which were found to be (5.0 mL HNO3 (70%): 3.0 mL HClO4 (70%) volume ratio of reagents, 200 °C digestion temperature and 2:00 hours digestion time for the digestion of 5.0 mL of milk samples. The mean concentration of Ca, Mg, Cu, Mn, Ni, Co and Cr were in the range of 1041.00–1609.00 mg/L, 72.00–122.00 mg/L, 0.0351–0.0819 mg/L, 0.0511–0.1019 mg/L, 0.0601–0.0684 mg/L, 0.0518–0.0814 mg/L and 0.0531–0.0809 mg/L, respectively for the seven pasteurized cow’s milk samples. In this study, the concentration of Ni was also found to be below the detection limits for pasteurized cow’s milk samples such as AA/B1, AA/B4, and AA/B6. However, the concentration of Pb was found to be below the detection limits for all pasteurized cow’s milk samples. Results indicated that there were significant differences (P<0.05) in most of the evaluated physicochemical parameters and minerals content among the seven pasteurized milk samples. The accuracy of the method for the determination of the selected elements was evaluated through recovery experiment and it lied within the range 98.0% to 114.1%, which is in the acceptable range (80–120 %). Generally, the levels of the selected physicochemical parameters and several metals were mostly found above the safe limits adopted from international food standards like WHO/FAO.