Australian scientists recycle more nutrients out of yoghurt milk waste
A University of Melbourne scientist and his research team have found a way to recycle the large amount of milk left over from making Greek yoghurt.
According to lead researcher, Dr George Chan, it takes four kilograms of milk to make just one kilograms of Greek yoghurt. When Greek yoghurt is produced a large amount of runny liquid called acid whey is created as a by-product. Dr Chan and his team have discovered how to separate the different components of the whey, selecting the most nutritionally beneficial parts while leaving behind the excess lactic acid that can be used to make ingredients for other products, including baby formula and other dairy products.
Dr Chen said that the acid whey is rich in protein, lactose, vitamins and minerals.
“Because of the way that Greek yogurt is manufactured, it is high in lactic acid. This makes the normally dry powder quite sticky after processing and the unpleasant taste associated with it, prevents acid whey from being used in other products,” Dr Chen said.
An electrically driven membrane process has been developed by Dr Chan’s team to remove the lactic acid from the whey. The beneficial proteins and lactose can then be easily extracted.
In Australia, more than one hundred million litres of acid whey is generated annually, but the figure is more than eight times higher in the United States.