Comparative analysis of cold microfiltration performance of cow and camel milk: Flux behavior, fouling mechanisms, and protein separation

This study presents a comparative investigation of the cold microfiltration (MF) behavior of cow and camel skim milk at 10 °C using a polyvinylidene fluoride (PVDF) membrane. The flux dynamics, fouling mechanisms, and protein separation efficiencies were evaluated to highlight compositional and structural differences between the two milk types. Camel milk consistently maintained higher flux and demonstrated a lower rate of flux decline compared to cow milk. Hermia model fitting indicated that intermediate blocking was the dominant fouling mechanism for both systems, with a higher fouling rate constant observed for cow's milk. Analysis of fouling resistance, scanning electron microscopy, Fourier transform infrared spectroscopy, and contact angle measurements confirmed a higher level of fouling in cow milk. Mineral profiling revealed that calcium was more closely associated with cow milk foulants, whereas sodium was more prevalent in camel milk. Protein quantification and SDS-PAGE confirmed the membrane's efficient retention of proteins, with minimal permeation of caseins from camel milk. The findings emphasize the importance of milk-specific properties in designing membrane-based separation processes and suggest that cold MF enables efficient casein–whey separation, with camel milk exhibiting lower fouling tendency and improved protein retention.