19-7 |
Pathogen containment and processing system for pilot scale challenge studies |
G. M. SAPERS, USDA-ARS-Eastern Regional Research Center, 600 E. Mermaid Ln., Wyndmoor, PA 19038-8598 and P. N. Walker, Dept. of Agricutural & Biological Engineering, Pennsylvania State Univ., 223 Agricultural Engineering Bldg., University Park, PA 16802. Current methods of washing and sanitizing fresh produce typically achieve microbial population reductions no greater than 1 or 2 logs. New disinfection technology is needed to achieve greater population reductions and assure microbiological safety. Such technology should be validated with commercial-scale equipment using produce inoculated with human pathogens, but facilities to conduct such studies are not available. In this paper, the establishment of a Biological Safety Level (BSL)-2 pilot plant facility at the Agricultural Research Service's Eastern Regional Research Center (ERRC) to meet this need will be described. This facility was developed jointly by ERRC and Pennsylvania State University (PSU) under a cooperative agreement that also funded short-term research to solve design problems, a PSU sabbatical position at ERRC, and a PSU graduate student. Pilot plant-scale washing equipment (dump tank, flat-bed brush washer, U-bed brush washer, dip tank), similar in design to commercial equipment, was designed, fabricated and installed at ERRC. This equipment provided precise adjustment of operating parameters, remote automated or manual control and data collection, corrosion and chemical resistance, and ease of modification. A chamber to safely contain the individual unit operations under negative pressure was designed, fabricated and installed at ERRC. Pass-throughs are provided for safe introduction and removal of inoculated and disinfected produce. The containment/processing line system is decontaminated by injection of steam at atmospheric pressure. Examples of recent studies in the BSL-2 pilot plant include extent of cross-contamination in dump tank operation, efficacy of brush washing with 80°C water, efficacy of washing with 200 ppm chlorine in a dip tank at elevated temperatures, effects of wetting agents and turbulence on efficacy of 5% hydrogen peroxide wash at 60°C in a dip tank, and application of sanitizing agents in the vapor phase. The new facility is a valuable national resource for developing effective decontamination technologies for fresh produce.
Session 19, Emerging technologies for enhancement of fruit and vegetable quality and safety
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