Currently, consumers demand the consumption of fresh products, without additives, easy to consume and minimally processed. But they retain their original organoleptic properties and a high level of safety. In order to offer solutions for these needs, research has increased in recent years non-thermal technology.
The non-thermal technology Includes all preservation treatments that are effective at room temperature. Which minimizes the negative effects of elevated temperature on the nutritional and quality parameters of food. The added value is that they allow you to reduce:
- Carbon footprint
- Treatment time
- Energy consumption
- The amount of water used by the food industry
The short-wave ultraviolet radiation (UVC) is a non-thermal technology that has been the subject of study in recent years. UVC works by changing the genetic material of microorganisms, blocking synthesis processes and inhibiting mitosis, affecting their ability to survive.
It is also effective against non-sporulated pathogenic bacteria and Listeria monocytogenes on Salmonella spp., as well as against bacterial spores, resistant to heat treatments such as pasteurization. Which guarantees the stability and microbiological safety of treated products.
Technologies applied in liquid food
Researchers at Center for innovation, research and transfer in food technology (CIRTTA) of UAB They study the application of alternative technologies to conventional ones. And UCV is one of the technologies recently included in its catalog.
Among the most interesting results obtained from this research are applications in products such as fruit juices, mainly clear apples, and also in infusions such as tea. The application of UVC in these two types of matrices represents an ideal scenario, given that they are slightly opaque matrices and have a high transmittance of UVC light.
In the case of green tea, tests were carried out with matrices inoculated with strains Escherichia coli, especially resistant to UVC. And also from Listeria monocytogenes, achieving a reduction of up to 5 Log even at low doses.
With apple juice, tests were done with Alicyclobacillus acidoterrestris, a sporulating bacterium responsible for the spoilage of heat-treated fruit juices. Well, it is especially adapted to an acidic environment and its spores are very resistant to pasteurization heat treatments, and it has been shown that it is easily destroyed by UVC radiation.
In the case of vegetable smoothies, the limitation represented by the difficulty in the passage of UVC light, due to its opacity, can be solved by using turbulent flows that ensure a greater degree of exposure of the microorganisms present to the action of UVC.
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