Description of non-thermal sterilization system combining medium-pressure ultraviolet lamps and filtration sterilization

<p>Through this paper, we aimed to describe the new concept of reducing carbon dioxide (CO₂) emissions from aseptic processing equipment as well as the concept and prospects of a non-thermal sterilization system (called GREEN ASEPTIC) combining medium-pressure (MP) ultraviolet lamps and filtration sterilization. Considering that filterable bacteria can pass through a sterile filter with a pore size of 0.2 μm, filtration sterilization has not been adopted in aseptic polyethylene terephthalate (PET) bottle filling systems for low-acid beverages. Therefore, we examined the ultraviolet (UV) sensitivity of twelve types of filterable bacteria and Bacillus atrophaeus spores via bench-scale collimated beam testing. The results showed that the UV resistance of the filterable microbes was about half or less that of B. atrophaeus spores. Additionally, the UV light emitted via MP lamps was more effective for the disinfection of these bacteria under our experimental conditions than low-pressure (LP) lamps. The sterilization effect on B. atrophaeus spores was also verified at 80 mJ/cm² with Atlantium's MP lamps. The addition of 1×10⁷ colony-forming units of B. atrophaeus spores to pure water at a flow rate of 18 m³/h killed all the spores, with a more than 7-log reduction value.</p><p>These results suggest that the combination of MP lamps and filtration sterilization can produce sterile liquids of the same quality as those produced by ultra-high- temperature (UHT) sterilizers and can be expected to significantly reduce CO₂ emissions from aseptic processing equipment.</p>