Melbourne scientists have completed new research into the way milk is digested, which it is hoped puts us on a path to new milks suitable for premature babies and others with milk intolerances.
Everyone knows milk is an important source of nutrition and sustenance, not just for human babies but all young mammals.
We also know the dairy industry is a key driver of the Australian economy, worth some $13 billion annually and directly employing 43,000 Australians (source: Dairy Australia).
So with a product so vital to human development and the Australian economy, you’d think we’d know a lot about what happens when we put it into our mouths - but you’d be wrong.
Of course Australian scientists are well aware of milk’s building blocks – carbohydrates, proteins, fat and the like - but mystery remains around the way milk, and specifically milk fats, are digested.
This lack of information applies to everything from human babies drinking their mother’s milk, right through to the way that adults digest cow, goat and other milk products.
That’s where scientists from the Australian Synchrotron and Monash Institute of Pharmaceutical Sciences come in, who are combining a technique called small angle X-ray scattering, a simulated digestion environment (including digestive enzymes, pH and salt levels) and, of course, some milk.
Milk products currently on the market that claim to be easier digest often base it on different additives, ingredients or manufacturing processes.
This research on the other hand, focuses on the actual nanostructure of milk, and how components of milk interact with the human digestive system.
The Melbourne scientists have discovered milk becomes highly geometrically ordered and structured at the nanoscale when being digested. The applications from that could include:
Dr Stefan Salentinig is from the Monash Institute of Pharmaceutical Sciences. He was conducting research at the Synchrotron just yesterday, and explains his work.
“We know about the building blocks of milk, and the fact that milk fat has a significant influence over the flavour, texture and nutritional value of dairy food,” said Dr Salentinig.
“Where there is a fundamental lack of knowledge and understanding is around the structural arrangement of milk fat during its digestion.”
Hydrolysis describes the process through which the addition of water enables the breakdowns of, in this instance, milk fat.
“Using beamline at the Australian Synchrotron we have identified that when milk is digested and hydrolysed, the by-products become highly organised,” said Dr Salentinig.
“This highly organised structure can influence the delivery of lipid-soluble milk components, which need to be transported through water before entering a cell via a membrane.
“That’s where it gets exciting. If milk, when being digested, breaks down into components that serve as a carrier to enter cell membranes, that has significant possible applications.
“We can look at exploring new, more efficient and more effective ways of getting life-saving drugs to work in people.
“We can consider new ways of making milk products that taste great and still retain lots of great vitamins and nutrients but are healthier, and products that make people feel fuller for longer.
“And if we can identify ways to make milk easier to digest, that could mean we could create dairy products more suitable for premature babies.”
Professor Andrew Peele, the Director of the Australian Synchrotron, said this is a great example of the applied science which is made possible through the facility.
“Great Australian science infrastructure enables great research and discoveries for Australia’s industries,” said Professor Peele.
“At this world-class Melbourne facility we use intense beams of light to reveal the structure and function of many different materials in a way that simply can’t otherwise be done.
“In this particular instance, our partnership with Monash means we are helping discover not just a new understanding of milk, but potentially new markets for it, which is incredibly exciting.”
Dr Salentinig said that a clear line of site between this early work and great potential outcomes will only be possible after more research.
“The next step in the study is to look at digestion of different types of milk, including human breast milk, to establish points of difference,” said Dr Salentinig.
The work has been funded by an Australian Research Council grant. Key scientists are Prof Ben Boyd, Ms Stephanie Phan and Mr Jamal Khan (Monash Institute of Pharmaceutical Sciences) and Dr Adrian Hawley (Australian Synchrotron).
The work is part of a study using the SAXS/WAXS beamline at the Australian Synchrotron to understand the digestion of in-vivo related food systems.
It is also part of a larger project on developing new methods of delivering drugs and bioactive molecules by exploiting lipid self-assembly processes.