Ultrasound technique offers faster, safer dairy processing
Australian food scientists, offers cost-savings to producers by
drastically improving the speed and hygiene of ultrafiltration,
writes Chris Mercer.
The ultrasound technique is intended to prevent the porous membranes used in ultrafiltration from getting clogged.
Dr Muthupandian Ashokkumar, one of the researchers on the project, told www.DairyReporter.com that membrane fouling remained the most significant barrier to greater adoption of ultrafiltration by the dairy industry.
"Ultrasonic enhancement of membrane operations could increase flux rates by 20 to 70 per cent, by reducing the extent of this fouling and enhancing mass transfer," said Ashokkumar.
He added that the increase in flux rates should mean a similar rate of savings on processing costs. He also said the technology could, in theory, be applied to any membrane operation, including microfiltration and nanofiltration.
Ultrafiltration uses porous membranes to siphon off whey, a by-product of cheese production, and separate different proteins according to their size. Some proteins recovered by this method can be re-used in food processing.
The problem is that, over time, proteins get lodged in the pores on the membrane surface, making it less effective as a membrane and less hygienic as a food processor.
This means membranes have to be cleaned and sanitised after each batch, adding to the time and cost of dairy processing.
Early research by the Australian team showed that 10 minutes of ultrasound could remove the proteins lodged in membrane pores.
Ashokkumar, of the University of Melbourne, said lab trials of the new ultrasound technique were already complete and that researchers were "working with collaborators at Food Science Australia to develop pilot scale trials on a full size spiral wound membrane unit".
Ashokkumar has received AUS$375,000 (€233,600) to investigate the use of ultrasound in dairy processing, in collaboration with Food Science Australia and the Dairy Ingredients Group of Australia.
The work is also being funded by a $3.5m government grant designed to explore the potential of ultrasound and other emerging technologies in food processing. The money was awarded to a consortium of researchers from the University of Melbourne, Food Science Australia, Swinburne University of Technology and CSIRO Plant Industry.
Work on the use of ultrasound to modulate the heat stability of milk proteins, aimed at enabling the manufacture of value-added dairy products, is just beginning, according to Ashokkumar.
"High-frequency sound waves can be used to generate chemical and physical interactions in milk components, which may then provide us with an opportunity to modify the processing characteristics and end-use functionality of dairy ingredients," he said.
For more information on this project see the recent article on >DairyReporter.com.