In a laboratory in Barcelona, researchers have found that milk can be made to surrender much of its water without the fire that has long defined the making of powdered food. Humanity has always fought to keep its nourishment from spoiling, and drying has been one of its oldest answers, though heat that preserves can also quietly alter what it preserves. Here an electric field, rather than a flame, tears the liquid into fine mist so that water slips away at room temperature, leaving proteins intact. The work remains early and cannot yet yield a fully dry powder, but it hints at a gentler path f
Electric Fields Concentrate Milk at Room Temperature, Offering a Heat-Free Route Toward Dehydration
No heat was applied. The room sat at 20°C.
Mark
So the headline is milk losing water with no heat. How does that actually happen?
Mimi
A strong electric field breaks the milk into millions of tiny droplets. Small droplets have lots of surface relative to their volume, so water leaves them readily even at 20°C.
Mark
And the flow rate was the deciding factor?
Mimi
Yes. At 0.2 mL/min almost nothing changed. At 0.01 mL/min, solids went from 12.3% to 36.8% in the 12% milk.
Luke
Worth noting that 0.01 mL/min is an extremely slow trickle. The reporting doesn't say how that squares with commercial volumes.
Mimi
Right, and the authors say throughput still has to be demonstrated. That's why scaling with multiple emission points is the next step.
Mark
The protein claim seems central. How solid is it?
Luke
It's phrased as results that suggest no alteration, based on gel electrophoresis of caseins and whey proteins. That's encouraging, but it's the researchers' interpretation from one test on skim milk. Vitamins and enzymes weren't mentioned as tested.
Mark
So what's the honest summary?
Mimi
A proof of concept. Nearly half the water removed, proteins apparently intact, but no dry powder yet.
Luke
And no energy figures. The pitch is lower energy use than heat, but that hasn't been measured yet.
Der Puls
- Conventional powdered milk production demands heat that can damage whey proteins, enzymes and vitamins, creating a quiet tension between preservation and quality.
- A strong electric field shatters milk into millions of microdroplets, and at low flow rates the solids content jumped from 12.3% to 36.8%.
- The team is testing flow rates, voltage and droplet travel distance, while trying multiple emission points to see whether the method can scale beyond the lab.
- Energy use and microbial stability of the final product remain unmeasured, and the method is being patented, so the technique is still far from the factory floor.
In a laboratory in Barcelona, researchers have found that milk can be made to surrender much of its water without the fire that has long defined the making of powdered food. Humanity has always fought to keep its nourishment from spoiling, and drying has been one of its oldest answers, though heat that preserves can also quietly alter what it preserves. Here an electric field, rather than a flame, tears the liquid into fine mist so that water slips away at room temperature, leaving proteins intact. The work remains early and cannot yet yield a fully dry powder, but it hints at a gentler path for delicate liquids that the old methods have always treated roughly.
In a clean room at the Institute of Microelectronics of Barcelona, a team pushed milk through a fine needle toward a collector ten centimeters away, with 29 kilovolts running between them. No heat was applied, and by the end the milk had lost a large share of its water. The study, published in Innovative Food Science & Emerging Technologies, is the first to explore electrospray as a way to dehydrate milk without heat.
The problem is familiar to the food industry. Powdered milk lasts for long periods without refrigeration, but making it is energy-intensive and exposes it to high temperatures that can damage sensitive proteins, enzymes and vitamins. Electrospray takes a different approach: a strong electric field overcomes the surface tension holding droplets together, splitting the liquid into ever smaller pieces so water evaporates readily at room temperature.
Flow rate proved decisive. At a high rate the solids barely changed, but at a low rate reconstituted milk rose from 12.3% to 36.8% total solids, and overall water content fell by nearly half. Gel electrophoresis showed that the caseins and whey proteins remained structurally unchanged.
The authors are candid about the limits. No completely dry powder has been produced, and capacity, energy efficiency and scalability are still unproven. Next come optimization work, multi-emission configurations for scale, and tests of energy use and microbial stability. The method may one day suit heat-sensitive liquids like milk and juice, but for now it remains a promising experiment far from industry.
In a clean room at the Institute of Microelectronics of Barcelona, a milk sample was pushed through a fine needle tip toward a collector 10 centimeters away, with 29 kilovolts running between them. No heat was applied. The room sat at 20°C, or 68°F. By the end, the milk had lost a large share of its water.
That experiment is the core of a study in Innovative Food Science & Emerging Technologies, from a team spanning the Institute of Microelectronics of Barcelona (IMB-CNM-CSIC) and the Center for Innovation, Research, and Technology Transfer in Food at the Autonomous University of Barcelona (CIRTTA-UAB). The authors are Bernat Perez Playà, Anna Zamora, Manuel Castillo and Llibertat Abad. They say it is the first time electrospray has been explored as a way to dehydrate milk without heat.
The problem they are addressing is familiar to the food industry. Powdered milk can be stored and shipped for long periods without refrigeration, but making it is energy-intensive and exposes the product to high temperatures. Heat can alter sensitive components such as whey proteins, enzymes and vitamins.
Electrospray works differently. A strong electric field overcomes the surface tension that holds liquid droplets together and breaks the liquid into millions of microdroplets. The researchers describe it as electricity shattering the milk, a single drop splitting into ever smaller ones, so that water evaporates more readily at room temperature. The technique is already used in tissue engineering, nutraceuticals and sensor manufacturing, but its use in food processing had barely been explored.
The experiments used a Fluidnatek LE-10 electrospray system, adapted to inject reconstituted skim milk at different concentrations and flow rates. Perez, who carried out the work for his doctoral thesis and is the study's first author, says the tests with skim milk were meant to establish the influence of critical variables: injection flow rate, the distance between the tip and the collector, and the milk's fat content.
Flow rate mattered most. At a high rate of 0.2 mL/min, the solids content of the milk barely changed. At a low rate of 0.01 mL/min, reconstituted milk with 12% total solids rose from 12.3% to 36.8%. The researchers attribute this to each droplet carrying a greater electrical charge relative to its volume at low flow, which encourages fragmentation and more evaporation. Overall, the water content fell by nearly half.
The team also measured droplet size, the amount of water removed, and, using gel electrophoresis, whether the main milk proteins, caseins and whey proteins, had changed structurally. Castillo, a professor of animal and food science at the UAB, says the results suggest that electrospray drying, unlike conventional thermal methods, does not alter these key components.
The authors are careful about the limits. Under the tested conditions no completely dry powder was produced, and processing capacity, energy efficiency and scalability remain undemonstrated. The method is being patented. Abad says the next steps are optimizing flow rate, applied voltage and droplet travel distance, trying configurations with multiple emission points to scale up, and evaluating energy consumption and the microbiological stability of the final product. The work points to a possible route for heat-sensitive liquids such as milk and juices, though it remains far from industrial use.
Bemerkenswerte Zitate
The results suggest that electrospray drying, unlike conventional thermal methods, does not alter these key components of milk.— Manuel Castillo, professor, Autonomous University of Barcelona
Next steps include optimizing flow rate, voltage and droplet travel distance, exploring multiple emission points, and evaluating energy use and microbiological stability.— Llibertat Abad, IMB-CNM-CSIC
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