Most people in the developing world need to produce their own food, and most of these people do it inefficiently, making food security far out of reach. People buy a cow, or camels for milk, goats or even sheep to get a daily, fresh supply of dairy. There is virtually no way to preserve it using refrigeration and boiling, or pasteurization, because it is too costly.
And think about all the crazy people going off grid. They too need a cheap and simple, low in energy way to save precious resources milked at the farmstead. Can a simple solar-based solution replace the fridge?
New, cost-effective answers lie in a simple and shocking technology. Researchers from Tel Aviv University have shown that simple electric pulses, in a process called electroporation, can kill the bacteria that contaminate milk. The process kills bacteria dead and the researcher of the study, Alexander Golberg, says this process can prolong milk’s shelf life.
“We are on a constant hunt for new, low-cost, chemical-free technologies for milk preservation, especially for small farmers in low-income countries,” says 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.”
According to the study, pulsed electric fields, an emerging technology in the food industry that has been shown to effectively kill multiple food-born microorganisms, could provide an alternative, non-thermal pasteurization process.
The stored milk is periodically exposed to high-voltage, short pulsed electric fields that kill the bacteria. The energy required can come from conventional sources or even come from the sun. The technology is three times more energy-efficient than boiling and almost twice as energy efficient as refrigeration.
An alternative for poorer countries
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,” says 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,” he says. “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.”
Image of goat milk via shutterstock