Physicochemical and structural properties of ultrafiltered buffalo milk and milk powder

Buffalo skim milk containing 10.20% total solids (TS), 3.96% protein, and 5.22% lactose was ultrafiltered at 50 degrees C to 23.50% TS and 16.44% protein. Contents of TS, fat, ash, and protein increased during UF, and lactose content decreased. The composition of permeate was influenced by the concentration factor during UF of milk; as the concentration factor increased, TS, protein, ash, and lactose content increased. The rejection coefficients after 77% weight reduction were 52.52% for TS, 94.95% for protein, 100% for fat, and 52.04% for ash. Rennet coagulation time decreased, and gel firmness increased after coagulation as the protein concentration of the milk increased. As examined by scanning electron microscopy, particles of buffalo skim milk powder had smooth surfaces, but most had dents of varying sizes. Particle sizes ranged from 2 to 55 micrometers in diameter