Development of a biotest method to assess integrity of aseptic package

A spray cabinet technique was developed to determine microbial integrity of aseptic packages. It was constructed to include two pumps and 32 nozzles to achieve complete coverage over all surfaces of the test packages. A cell culture of Lactobacillus cellobiosus was sprayed onto the packages through the nozzles during testing. Standard pinhole orifices were used to determine the efficiency of the spray cabinet technique to detect pinholes. A ten micron hole was detected after 15 minutes of spraying, while a 5 micron defect was detected after 30 minutes of spraying. The percent defects increased as the pinhole size increased. The spray cabinet technique provided better detectability compared to an immersion methods. Aseptic juice packages were exposed to dynamic testing, and the package integrity assessed using the biotests. A high level of defects was found using the spray cabinet technique. More loss of integrity was observed for packages located in the corner of the shipping cartons. The most damage was observed in corner packages of shipping containers stacked 5 high.