Digestion specialist, Dr Andrew Clulow, from the Monash Institute of Pharmaceutical Sciences (MIPS) is continuing to break ground in the world of milk and infant nutrition discoveries with a new study that has shown that mixing cow milk fat with canola oil can replicate the structure of human breast milk during digestion.
The study, published in the Journal of Colloid and Interface Science, found that the structuring of digesting human milk was replicated in emulsions containing an optimum mixture of cow milk fat and canola oil, with the fats being mixed via a high-energy processing technique forcing them together into mixed fat droplets.
Milk is nature’s nutrient delivery vehicle and the primary source of nourishment for infants in the first year of life. Milk substitutes, such as infant formulae, are commonly made by blending together vegetable oils with each other or cow milk fat, forming a similar overall fatty acid content to human milk.
Dr Clulow, who is a key member of the Eureka Prizes award-winning Monash Pharmaceutical Milkshake Team – a group of scientists at MIPS led by Professor Ben Boyd, said: “Despite replicating the human milk composition, the way some infant formulae behave during digestion does not always replicate human milk and, furthermore, the complex composition of fats found in many of these substitutes are not always necessary to replicate the self-assembly behaviour of human milk.”
“We hypothesised that by mixing cow milk fat with canola oil we would be able to replicate the structuring of human milk by balancing fatty chain lengths and saturation levels. We found that when the ratio is right, we were able to achieve this in a lab setting through an ultrasonication process.”
“Different milks contain different types of fats based on the length of the fatty chains in the fat molecules and their level of unsaturation. Cow’s milk contains relatively high amounts of shorter chain fats and saturated fats, whilst canola oil is nearly all long-chain unsaturated fat. The fats of human milk lie somewhere in the middle, so by mixing cow milk fat and canola oil we can generate a fat mixture that looks more like human milk chemically – and now we’ve shown that it also forms the same structures as human milk during digestion.”
Earlier this year Dr Clulow also published his ‘Milk Mimicry‘ study which showed that simple fat mixtures can imitate the behaviour of vastly more complex human and cow milk fats when digested.
Dr Clulow says: “This year we have now published two examples showing how we can mix, match and blend different fats together to behave like human milk in terms of the way their fats structure during digestion. From here, the focus is to see if that structuring is truly important in a nutritional sense.”
“The next step is to see how the fat structuring is altered when we introduce fat-soluble nutrients into the milk and to see how the digestion products might assist absorption of these fat-soluble nutrients into the body, ultimately leading to enhanced nutritional substitutes for infants down the track – more work is required before we get it to this stage.”
The Monash Pharmaceutical Milkshake Team was established to understand the behaviour of milk and milk-like systems under digestion and how this can be applied for oral drug and nutrition delivery. Dr Clulow’s research is funded by the Australian Research Council through a Discovery Early Career Research Award and the experiments were made possible through the Australian Synchrotron located adjacent to Monash University’s Clayton campus.