Process efficiency of casein separation from milk using polymeric spiral-wound microfiltration membranes

Area of Science:

• Dairy Science
• Food Engineering
• Membrane Technology

Background:

• Microfiltration is crucial for separating casein micelles from milk serum proteins (SP) for cheese production.
• Ceramic membranes are common, but spiral-wound (SW) membrane efficiency for this application is less understood.

Purpose of the Study:

• To evaluate the impact of SW membrane pore size (0.1 and 0.2 µm) on milk protein separation.
• To assess separation efficiency and energy consumption of SW membranes during concentration and diafiltration (DF).

Main Methods:

• Tested SW membranes with 0.1 µm and 0.2 µm pore sizes in total recirculation mode.
• Conducted concentration-DF experiments with the optimal 0.1 µm SW membrane.
• Compared SW membrane performance to a 0.1 µm graded permeability (GP) membrane.

Main Results:

• Pore size did not affect permeate flux, but the 0.2 µm SW membrane led to significant casein loss.
• The 0.1 µm SW membrane showed higher SP rejection (0.75-0.79) than the GP membrane (0.46-0.49).
• The 0.1 µm SW membrane demonstrated lower energy consumption (0.015-0.024 kWh/kg) compared to the GP membrane (0.077-0.143 kWh/kg).

Conclusions:

• 0.1 µm SW membranes are a promising, energy-efficient option for concentrating casein for cheese making.
• GP membranes offer greater permeability and a longer lifespan, presenting an alternative consideration.