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Bigelow's general method revisited: Development of a new calculation technique |
R. J. SIMPSON1, C. A. Acevedo1, S. F. Almonacid1, and A. TEIXEIRA2. (1) Procesos Químicos, Biotecnológicos, y Ambientales, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, 5632, Chile, (2) Agricultural & Biological Engineering Dept., Univ. of Florida, PO Box 110570, Gainesville, FL 32611-0570 Thermal processing of foodstuffs should aim at maximizing the destruction of microbial organisms and spores to produce microbiologically safe products while reducing the loss of quality factors and reducing processing time. The objective of this research study was to develop a comprehensive procedure to fully implement the General Method (developed by W.D. Bigelow during the 1920s) in a computer program and with the complement of heat transfer theory enhance its ability to manage different processing conditions (i.e. RT). A general computer-based procedure was developed to fully implement the Bigelow General Method. The procedure included: a) Evaluation of thermal processes data (obtained experimentally and/or by simulation), b) Evaluation of thermal processes data for a specified F value, and c) Evaluation of thermal processes data for different conditions than the experimentally recorded temperature (retort temperature RT, initial temperature IT, etc.). The new procedure was experimentally validated and extensively tested against the formula method. In many cases reduction in process time evaluation was found when the new procedure was compared with the traditional and improved formula methods. Reduction in process time was due to the advantage of this procedure into accurately considering the lethality of come-up time (C.U.T.) and also because its accuracy in the cooling step evaluation. The new calculation technique has the same ease of use as Ball's Formula Method but with better accuracy.
Session 13, Food Engineering: Thermal processes
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