PROCESS EXPO | Expert in Residence
E-Beam Package Sterilization
Steve Smith | Purdue University
In aseptic processing and packaging, you must pre-sterilize both the package and the product before you seal the product into the package.
Traditionally, companies have used three methods of package sterilization:
- Steam or superheated steam. Other than for sterilizing metal cans, however, steam has limited use.
- Gama radiation. This method is great for sterilizing institutional-size bags, but its use for the retail market is limited.
- Hydrogen peroxide (35% concentration). This method was approved for use in 1982 and remains the primary sterilant for retail packaging.
Concerns about hydrogen peroxide
While hydrogen peroxide is the most popular package sterilant, there are several concerns regarding its use:
- Restricted line speeds due to long residence times. The peroxide must contact the package at an elevated temperature and remain in contact for a period of time. The peroxide must then be dissipated using hot sterile air so that residue levels in the final product are less than 0.5 ppm.
High costs. The cost of both the peroxide and the energy required to heat it can be high. Also, the Department of Homeland Security considers 35% concentrated hydrogen peroxide a scheduled chemical, which means it must be inventoried and controlled1.
- Use of chemicals and environmental impact. Consumers are concerned about the use of chemicals in the food industry and the effects of those chemicals on the environment.
Electron Beam: An alternative package sterilization solution
Electron Beam, or E-Beam, is a package sterilization method that eliminates many of these concerns:
- The required residence time is short, which means higher line speeds.
- Less energy is needed to produce e-beams than to heat peroxide.
- It doesn’t contain chemicals.
Tetra Pak, the largest maker of retail aseptic fillers, recently announced a new Tetra Pak® E3 platform filler using E-Beam technology. According to Tetra Pak, this system can increase line speeds by 60%, sterilizing up to 40,000 packages per hour. They also claim a 33% decrease in energy costs 2.
Companies are already using E-Beam sterilization effectively. For example, Shibuya, a Japanese aseptic filler company, makes a filler that uses E-Beams to sterilize PET bottles. The bottles are inverted to sterilize both ends, and then sterile air sweeps away any ozone. Shibuya claims that this method has a smaller footprint and is better for the environment than peroxide3.
With the various costs associated with peroxide — monetary, environmental, and so on — companies are in the market for new sterilization technologies. If Tetra Pak's claims hold up, E-Beams might be just the solution.