Gentle milk fat separation using silicon carbide ceramic membranes

Abstract

Due to their high hydrophilicity, ceramic silicon carbide (SiC) membranes are suitable for fat separation from raw milk, as alternative to centrifugation. The filtration performance during separation of fat globules (MFGs) from raw milk showed 95% fat separation at 15 °C, 93% at 25 °C, 88% at 35 °C and 91% at 50 °C, while permeating skimmed milk with a fat concentration ranging from 0.11 ± 0.03 to 0.34 ± 0.23% (w/w). The filtration time ranged from 12 to 106 min, respectively for 50 and 15 °C. Fouling of the membranes was investigated using scanning electron microscopy and elemental composition by energy dispersive X-ray. The SiC membranes showed a defect-free morphology, excellent water permeability and no irreversible fouling after the filtration process. Separation at 50 °C showed a higher distribution of larger MFGs in the permeate due to increased flexibility of the MFGs. Industrial relevanceMicrofiltration has previously been proposed to be a gentler separation method compared to traditional centrifugation. In this study, for the first time was demonstrated that highly hydrophilic ceramic silicon carbide (SiC) membranes are an efficient process for separation of fat from raw milk. The effect of filtration temperature on filtration performance and properties of the resulting streams provided new insights for industrial application of this process.