The Rheological Behavior of Raw Human Milk

Milk is a biological fluid produced in the mammary glands of all mammals during and after pregnancy. Like other biological fluids, the transport of milk in the ductal system of the breast is essential to good health during lactation. Content of mammalian milk is species-specific with variations throughout lactation and between individuals. Unlike other biological fluids found in humans, the rheological properties of human milk have not been comprehensively studied. The present study reviews previous work done on the rheology of milk from various mammals, including humans, defines the flow conditions found within the human breast, examines the content of human milk as it relates to the flow properties, and presents experimental work performed on raw human milk. The results of the experimental work demonstrate that raw human milk is a time-dependent shear-thinning non-Newtonian fluid with gel-like behavior at rest. The findings of this study indicate the need for further research which is currently underway.