It may come as a surprise to you that intense, split-second pulses of ultraviolet (UV) light can efficiently and effectively kill micro-organisms on the surfaces of packaging materials such as yogurt cups or bottle caps. What may be even more promising is that Claranor, the French firm that pioneered pulsed UV sterilization several years ago, is now conducting large-scale testing of their technology on sugar syrups used in producing soft drinks.
Preliminary in-house tests were promising. If UV disinfecting is indeed proven to work as well with ingredients as it does on packaging, it could revolutionize not only beverage production but food production in general. UV light energy used in this way could have the potential to kill pests and micro-organisms without negatively impacting the qualities of the food ingredients, as often happens with heat-based processes.
Here's how UV pulses disinfect packaging components: the UV light pulse is created using Xenon lamps paired with capacitors. Capacitors are components that build up electrical voltage prior to discharge; when these discharge, they create a flash of light energy that peaks at 1 megawatt, according to Claranor's web site, which is a tremendous amount of energy for the cells of target micro-organisms. This process bathes the treated object at a rate of 1 kilowatt per square centimeter of surface. The flashes are controlled, concentrated, and directed by aluminum reflectors that are, of course, custom-designed for each installation at a production and packaging line. The pulsed light generated by this process is particularly efficient because the housings of the Xenon lamps are made of quartz. Quartz optimizes the optical energy generated and little is wasted or lost.
According to Claranor, the pulsed UV light completely destroys micro-organisms because of two effects it has, photochemical and photothermal. The photochemical effect is that it ruptures the cells' DNA and, as a result, the cell metabolism is blocked and the DNA cannot replicate, with both leading to cell death. The photothermal effect of the pulsed UV light is to cause the internal temperature of a cell to rise to the point where it explodes, and it does this without affecting the temperature on the outer surface of the cell.
Innovation is integral to Claranor, an enterprise that introduced pulsed light sterilization on an industrial level in 2004. Located in the southern region of France, the company has won numerous honors and awards at many industry events and shows for its leading edge technology.
In its corporate culture, Claranor focuses on advancing its technology and claims to maximize efficiency by not only custom designing reflectors based on each product being sterilized but also by determining the most economical balance between energy use and Xenon lamp life. In other words, it is easier to quickly destroy micro-organisms by using a lot of electrical power, but that is accomplished at the expense of shortening the life of the lamps. Clarinor calculates for its clients the optimum balance of electrical energy and Xenon lamp replacement rate to maximize cost savings for its sterilization process.
If the pulsed UV sterilization technology can be adapted for food production (as the company's preliminary tests indicate), you would expect to gain not only the cost efficiencies of the optimal use of electrical power and light but also the advantage of avoiding chemicals and (possibly) heat-based sterilization processes.
