Pulsed electric fields could be used in developing countries to preserve milk

Short pulsed electric fields could provide an energy-efficient alternative to thermal pasteurisation in developing countries. That’s according to a team from Tel Aviv University (TAU) led by Dr Alexander Golberg of TAU’s Porter School of Environmental Studies.

Through a process called electroporation, bacterial cell membranes are selectively damaged. Applying this process intermittently prevents bacteria proliferation in stored milk, potentially increasing its shelf life.

According to the study, pulsed electric fields could provide an alternative, non-thermal pasteurisation process that could hold benefits in developing countries as the technology is three times more energy-efficient than boiling and almost twice as energy efficient as refrigeration.The energy required can come from conventional sources or from solar power. 

“We are on a constant hunt for new, low-cost, chemical-free technologies for milk preservation, especially for small farmers in low-income countries,” said Dr Golberg. “For 1.5 billion people without adequate access to electricity, refrigeration is simply not a possibility and boiling does not preserve milk’s freshness over time.”

Pulsed electric fields preservation technology can be powered using small, family scale solar panels

In developed countries, bacterial growth in milk is managed with refrigeration. But certain pathogens like listeria monocytogenes are less sensitive to low temperature so can proliferate during transportation and in storage.

“Refrigeration slows the bacteria’s metabolism, but pulsed electric fields kill them,” said Dr Golberg, “They are a fundamentally different approach to controlling microorganisms during storage.

“Our model shows that pulsed electric fields preservation technology does not require a constant electricity supply; it can be powered for only 5.5 hours a day using small, family scale solar panels. I believe that this technology can provide a robust, simple, and energy-efficient milk preservation system that would decrease the amount of wasted milk, thus increasing the income of small farmers in developing countries.”

Dr Golberg is currently exploring partnerships with interested agencies to develop an affordable device to reduce food waste and increase small farmers’ incomes.