Validation of an Aseptic Packaging System of Liquid Foods Processed by UHT Sterilization

Abstract

The Ultra High Temperature sterilization process (UHT) followed by aseptic filling, requires validation of the operational conditions, including air quality control, equipment operation and good manufacturing practices to avoid recontamination of processed food. The objective of this study was to validate an aseptic filling system applied to sterile liquid foods through microbiological study of air quality and processing practices. It was used a Merck MAS-100 Eco to collect air samples inside the aseptic filling and process surrounding area, being inoculated in PCA (bacteria) and PDA (yeasts and molds) medium. In addition, in the aseptic filler were collected air samples by petri plate opened during two hours in the filling process and four hours after processing, to the evaluation of the microbiological filter integrity. This evaluation were made in 13 process repetitions, and the results were compared to the ISO 14644 and Fung scale parameters, where the aseptic filler counts resulted in an absence with the use of the air sampler, and for the plates exposed for 2 h during process, a critical condition, showed a 100 % absence for aerobic mesophilic bacteria and 71.4 % for fungi. The 4 h exposition counts showed a 100 % absence for bacteria and fungi, concluding for the filter integrity. In the surrounding process area, the results were below the allowed limit of 300 cfu.m-3 air. Personnel (operators) received training in the operational procedures related to the good manufacturing practices and were evaluated with the use of a checklist, also determining the critical control points of process steps. This training results in failure control and improvements in microbiological results. The checklist showed 95 % compliance and in each process was made training operational improvements, and the critical points (UHT sterilization, filling and packaging closing) were controlled. The results validate the aseptic filler system, highlighting the importance of the staff training and process monitoring.