MELBOURNE researchers have discovered how milk is ­digested, paving the way for the development of vitamin-loaded milk for premature ­babies, weight-loss drinks, or new drug delivery systems.

Little has been understood about milk’s molecular structure and how its fats interact with the digestive system.

Monash Institute of Pharmaceutical Sciences research fellow Dr Stefan Salentinig found that milk’s unique structure, an emulsion of fats, nutrients and water that don’t usually combine, enhances its digestibility.

His team chemically recreated the digestive system in a glass beaker and added cow’s milk, analysing the real-time digestive process with the Small Angle X-ray Scattering beam line at the Australian Synchrotron.

Instead of joining as large fat masses, they found that milk arranged itself in a highly-ordered structure, which helped the protein lipase absorb milk’s healthy fats into the body.

They found that milk ­arranged itself in a highly ­ordered structure, which helped milk’s healthy fats to be absorbed into the body.

“As soon as your body starts to digest, the (protein) lipase starts to form this highly geometrically ordered nanostructure,” Dr Salentinig said.

“It’s similar to a sponge or coral, with a huge internal surface area because of lots of channels inside.”

When milk breaks down in the stomach, these smaller components become carriers that can cross cell membranes into the circulatory system.

Dr Salentinig said unlocking the molecular structure of milk digestion provided a blueprint for adding nutrients to milk, which could lead to the creation of vitamin D- and A-loaded milk for premature babies, or of a drink that slowed digestion so people feel full for longer.

He said by harnessing milk’s ability as a “carrier”, new forms of drug delivery could be developed, allowing for a controlled release of medication over time.

The findings were published in the journal ACS Nano.