Pasteurization has always relied on significant amounts of heat. However, a new technology can achieve the same function without this heat, thereby preserving a key protein intact, as reported by DairyReporter.

UV Light

Pasteurization is an important part of making milk safe for consumption since, otherwise, according to the UK Food Standards Agency, the risk to human health is significant.

But what if the same work could be done without heat, leading to a less energy-consuming process? Danish company Lyras uses UV light to remove bacteria from milk without the need for any heat.

Initially dubbed "cold pasteurization," the process has been rebranded as "raslysation," a combination of the first three letters of the company's founder's name, Rasmus Mortensen, and the Danish word "lys," which means light.

The process, the company predicts, has the potential to save 60-80% of water consumption and 60-90% of energy consumption compared to pasteurization. Because it is less energy-intensive than pasteurization, it is, the company suggests, both more sustainable and economically viable by comparison.

How the Technology Works

Raslysation uses "germicidal" UV light to modify the DNA of microorganisms to prevent them from reproducing, stated Mark Kalhøj Andersen, Lyras' new CEO, to FoodNavigator.

The antibacterial potential of UV light has long been known, though previously, it was only used for transparent liquids like water. Normally, it couldn't penetrate very far into opaque liquids like milk, only passing through 0.1 millimeters of it.

Origins of Pasteurization

Named after French scientist Louis Pasteur, who in the 1860s realized that abnormal fermentation could be prevented in beer and wine by heating, the prospect of using pasteurization in dairy products was first suggested by German chemist Frans von Soxhlet in 1886.

However, with Lyras' technology, the light can penetrate the liquid. "That's the innovative part of our technology. We can treat liquids where light can't naturally penetrate into the liquid, can't reach organisms," Andersen told us.

To achieve this, Lyras places any liquid it treats into a polymer coil, through which light can penetrate. The turbulence created by the liquid's movement through the coil creates rapid variation in which part of the liquid eventually reaches the inner surface of the coil, meaning, Andersen told us, that all microorganisms in the liquid will eventually reach the point of light exposure and be altered by light.

Benefits of the Absence of Heat

There are a number of differences in the effects of Lyras' technology compared to traditional methods like pasteurization.

"In terms of microbiology, we can achieve the same microbiological reductions as pasteurization," Anderson told us. But the technology is also capable of preserving certain proteins intact, such as whey proteins, where otherwise, during the traditional pasteurization process, they would not have been.

"Heat (pasteurization) changes proteins. It denatures them, so they leave their native state, just like boiling an egg will change the native state of proteins and solidify it instead of liquid. It's practically the same thing we see here. However, light doesn't affect native protein, as we can measure it."

Lactoferrin

Lactoferrin, one of the key components of whey protein, has been shown to have antimicrobial, antioxidant, and anticancer properties. Lyras' technology can ensure that lactoferrin remains in its most natural state. Thus, it has partnered with companies like Beston Global Food Company to produce lactoferrin as a product.

In short, the main benefits of the technology are "preservation of native proteins, yet still controlling microbiology in the liquid," Andersen concluded.

Another vitamin often affected by pasteurization is riboflavin or vitamin B2, an antioxidant that can reduce the effects of oxidation in other molecules. "UVC, which is used in our technology, has little or no effect on the degradation of vitamin B2," said Thomas Yssing Michaelsen, Lyras' research chief, to FoodNavigator.

However, exposure to UV light can affect flavor and therefore its usage levels need to be controlled. "For some elements, we have a threshold; we can't go over it because then the flavor change is perceived as an unpleasant flavor," Andersen told us. "This is a limitation of the technology."

Can it be Implemented at scale?

In Lyras' native Denmark, the technology has been well received. However, in other markets, the validation process is still ongoing.

A particularly challenging market is Germany, where a regulation makes implementing the technology difficult. While in most of Europe, Andersen told us, UV light is defined from a regulatory standpoint as light, in Germany, it's defined as ionizing radiation, meaning it's more difficult to approve.

Despite the novelty of the technology, installing the process hasn't posed significant hurdles. "The feedback we get from wherever we've done the installation on a large scale is that they're surprised by how smooth the installation is.

"We don't need anything else but electricity and integration into a system. But that can be manual as well. Likewise with the cleaning process: because there's no heat, it's just a simple cleaning process. So, practically, where heat would normally require steam generation, we just need electricity. So, I would say the technology can definitely go towards even small-scale farmers." (Photo: Dreamstime)