17H-9 |
|
A. K. SINGH JASROTIA1, T. K. Palazoglu2, J. Simunovic1, K. R. Swartzel1, and K. P. Sandeep1. (1) Dept. of Food Science, North Carolina State Univ., 39 Schaub Hall, Box 7624, Raleigh, NC 27695-7624, (2) Dept. of Food Engineering, Mersin Univ., Ciftlikkoy, Mersin, 33342, Turkey Aseptic processing of low-acid foods containing large particles is an emerging technology. Most multiphase process validation methods employ simulated particles to contain residence time tags, thermo-sensitive implants and/or bio-loads for temperature detection, time-temperature integration and bactericidal efficiency confirmation. Such particles need to have conservative (fast-moving and slow-heating) characteristics. Appropriate procedures are needed for their design, fabrication and validation. Our objective was to fabricate and test conservative (slow-heating) simulated particles as carriers for thermo-sensitive implants and bio-loads in the validation procedure for aseptic processing of shelf stable low-acid multiphase foods. Additionally, to devise and implement a procedure for testing of fabricated particles based on heat penetration. Custom developed CPD (Conservative Particle Design) software was used to determine the wall thickness and cavity dimensions of ½ inch cubic particles for validation of aseptic processing of foods containing ½ inch cubic potato and carrots pieces. Particles with a minimum wall thickness of 2 mm were fabricated from polypropylene and polymethylpentene polymers. Duplicate samples of simulated and real (potato and carrot) cubic particles were fitted with thermocouple sensors and heated under atmospheric (<100 C) and pressurized (autoclave, <125 C) conditions. Heat penetration was monitored and compared to test conservative thermal behavior of simulated particles. Heated to 100C, neither polypropylene nor polymethylpentene particles exhibited conservative heat penetration characteristics compared with ½ inch potato and carrot cubes. With pressurized heating up to 125C, only polymethylpentene particle characteristics were confirmed as appropriately conservative. Systematic procedures for design, fabrication and testing of simulated food particles to be used for experimental validation of safety of aseptic processing of multiphase foods are needed to generate particles with appropriate characteristics. Availability and reduced cost of such particles would reduce the complexity of process documentation and filing with regulatory agencies and bring aseptic multiphase foods closer to commercial reality.
Session 17H, Food Engineering: Thermal processes
|