Ultrafiltration can be defined as a pressure- driven membrane process (2-15bar) that can be employed in the separation and condensation of substances with molecular weights between 1-100 KD. The pasteurized, non- homogenized whole milk was ultrafilterd at 50?C, 5 Bar with APV ultra filtration system (51 spirally wound, poly sulfone filter, MWCO=20 K Dalton, DDS) to evaluate all milk of its contents’ Coefficient of Rejection. Then, total solid, total nitrogen, non- protein nitrogen, protein, fat, lactose, ash, calcium, sodium and potassium were analyzed at a 95% confidence level. The percentage coefficient of rejection for these components were respectively reported as: (55.67±0.695), (93.94±0.89), (5.85±0.39), (99.63±0.24), (100), (0.835±0.21), (31.30±2.89), (59.77±1.18), (9.2±0.77), and (11.47±0.5). The rejection coefficients of milk protein were evaluated through discontinuous SDS-PAGE (10-20% acryl amide), which revealed that ?-lacto-albumin, ?-lactoglubolin casein and casein hydrolysis contents were respectively rejected as: (96.68±1.725), (99.18±0.46), (100), (98.39±1) through ultra filtration membrane
)