Study on Physical Properties of Goat and Cow Milk Powder

Physical properties of milk powder are important for the final steps of the drying process as well as for further use of it. The chemical composition and their physical properties are the basic quality indicators of milk powders. The variation in the milk powders properties comes from the raw material, drying methods and the numerous chemical reactions that could happen during storage because of the temperature, relative humidity and time. This study evaluated physical properties of goat and cow milk powders. The most commonly available two different brands of goat milk powders (GMP1 and GMP2) were selected for the study. Insolubility index of powder was determined using method described by GEA Niro analytical method A 3. The Water activity (aw) of goat and cow milk powders was determined using method described in Public Health. For the analysis of sample, the appropriate amount of powder was taken in glass petri dish and colour measurement was performed according to the three-colour coordinates (L*, a*, b*) with chromameter. The chroma, yellowness index, whiteness index and browning index were calculated. The Statistical analysis was done by using the completely randomized design (CRD). Data are expressed as the mean ± standard deviation. Cow milk powder showed lower L* and higher b* values (P<0.05) than GMP1 & GMP2, while both goat milk powder had lower browning and yellowness indices. An average a* value was varied from -3.25 to -3.90 in all powder samples. Cow milk powder had the highest insolubility index, surface free fat, loose bulk density, and better flowability. Bulk density ranged from 0.39–0.49 g/ml, and wettability of all powders exceeded 30 min. Physical properties of milk powders have significant impact on products formulation. The physical properties of milk powder influenced by the various technological parameters used during production. Hence it is important to analyse the physical properties for various use and marketing.