Key parameters and strategies to control milk concentrate viscosity in milk powder manufacture

Milk concentrate (MC) viscosity is a key process control parameter in the manufacture of dairy based powders that affects both process efficiency and powder functionality. If the viscosity of MC is too high, various processing issues can arise, i.e., pump blockages, fouling, poor atomisation, product rework and production downtime. Viscosity of MC is dependent on various intrinsic (e.g., total solids content, protein: lactose ratio, mineral profile, pH) and extrinsic (e.g., temperature, agitation, high shear) parameters. It is therefore necessary to understand the effects of these parameters on the viscosity of MC to maintain an optimal process. This review focuses on outlining the parameters that affect the viscosity of MC and recent advances in processing strategies to reduce viscosity of MC prior to spray drying during powder manufacture.