29D-6 |
Conservative process evaluation for multiphase aseptic processing: magnetic sensor arrays and thermo-magnetic switch implants |
T. K. PALAZOGLU1, J. Simunovic2, K. P. Sandeep3, and K. R. Swartzel2. (1) Department of Food Engineering, Mersin University, Ciftlikkoy, Mersin, 33342, Turkey, (2) Dept. of Food Science, North Carolina State Univ., Schaub Hall, Box 7624, Raleigh, NC 27695-7624, (3) Food Science Department, North Carolina State University, 129 Schaub Hall, BOX 7624, Raleigh, NC 27695 Aseptically processed and packaged low acid food products containing particles remain an area with high industrial potential, but no commercial presence in the North American market. Inexpensive and robust thermal process monitoring and validation tools and devices remain a weak link in commercialization efforts. Our objective was to develop and test particle flow monitoring tools conforming to requirements for conservative process evaluation and validation and a potential for integration of residence time measurements with time-temperature history recording and bio-validation using bacterial spores. Conservative particle design incorporating thermal (slow heating) and flow (fast moving) components was defined and implemented for simulated 0.5 inch cubic particles fabricated from machined polymer. Giant magneto-resistive sensors were assembled in 8-sensor arrays and arranged linearly along heating and holding sections. Sensor signals from each array were collected and amplified using an amplifier and acquired by a 32-channel high-speed computer data acquisition system at 90 Hz rate. This system provided a total of 256 sensing locations along the monitored length of process equipment. Thermo-magnetic switch implants with predetermined temperatures of magnetic signal change (125C and 138C) were tested using a bench-top magnetic field testing installation as well as the data acquisition system equipped with magnetic sensor arrays. Functionality and sensitivity of thermo-magnetic switch implants within the fabricated simulated particles were confirmed using the bench-top testing unit and a 32-channel data acquisition system at tested switch temperatures (125C and 138C). Particle design parameters provide for future integration of bacterial spore loads into individual load carrier cavities. These results demonstrate the feasibility of implementing a conservative process monitoring and validation methodology for continuous thermal aseptic processing of low acid food products containing particulates. Developed tools could be used by food processors to collect process validation data needed for process safety documentation and filing with regulatory agencies.
Session 29D, Food Engineering: Thermal processes
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