Pulsed electric fields - a viable alternative to pasteurisation

Controlling pathogen growth in milk by means of refrigeration simply isn’t feasible in some low-income countries due to the high cost of infrastructure and the lack of a permanent electricity supply. In addition, pathogens like Listeria are less sensitive to low temperature and can proliferate even when milk is refrigerated.

“There is a constant search for new, low-cost, chemical-free technologies for milk preservation, especially for the small farmers in the low-income countries,” said Alexander Golberg, PhD of Porter School at Tel Aviv University.

Golberg and colleagues have developed a technique using high-voltage, short pulsed electric fields that selectively damage cell membranes, killing the contaminating bacteria by a process known as electroporation.

“In many rural places refrigeration is not possible and its alternative, lactoperoxidase system may be misused to disguise milk produced under poor hygienic conditions as Codex Alimentarius. This development not only holds great promise for unravelling many aspects of the complex wound healing process but can also potentially lead to new therapies. We believe that this model will enable other laboratories to learn and uncover new aspects of adult tissue growth and development.”

An emerging technology in the food industry, pulsed electric fields has been shown in multiple studies to effectively kill multiple foodborne microorganisms. It could provide an alternative, non-thermal pasteurisation process in areas where large-scale pasteurisation facilities don’t exist.

“In the storage application, developed in this work, we use the fundamentally different approach for microorganism control. Refrigeration, the major milk preservation technology, slows the bacteria metabolism; pulsed electric fields kill them,” Golberg said.

“Moreover, our model shows that pulsed electric fields preservation technology does not require a constant electricity supply and can be powered 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 wasted milk thus increasing the income of the small farmers in developing countries.”

The study was published in the journal TECHNOLOGY