Nutrient Delivery by Digesting Dairy Fats

Milk is nature’s nutrient delivery vehicle and one of the most complex fat mixtures known with over 400 different fatty acids esterified onto glycerol molecules to produce potentially thousands of triglycerides. We survive simply on our mother’s milk or its substitutes for the first six months of life. From then on, bovine milk and associated dairy products are often a mainstay of the infant and adult diet. It is known that early supplementation with either infant formula or bovine milk can have detrimental ongoing health outcomes for children. What is not presently known is how the different lipid compositions of the different milks and substitutes influences nutrition. This project will examine the influence of fat composition on the disposition of fat-soluble nutrients in intestinal colloids at different stages of milk lipid digestion.

The student will work with the supervisors to generate simulated intestinal colloids that mimic those of human and bovine milk at different stages of digestion. Spectrophotometric and fluorescence techniques will be used to quantify the partitioning of nutrients between the milk-mimicking colloids and lipophilic membranes. Where required, small angle X-ray scattering at the Australian Synchrotron will be used to determine the effect of nutrient incorporation on the nanoscale structuring of the intestinal colloids. The results will be compared with digested milk fats to show whether or not the lipid composition plays a key role in enhancing the delivery of fat-soluble nutrients.