Journal of Chemical Engineering & Process Technology
Open Access
ISSN: 2157-7048
+44-20-4587-4809
ISSN: 2157-7048
+44-20-4587-4809
Arthur A Teixeira
University of Florida, USA
Posters & Accepted Abstracts: J Chem Eng Process Technol
Thermally processed foods in flexible packages have created the need to operate retorts capable of delivering controlled overriding air pressure during processing to counter internal pressure buildup that would otherwise burst or damage the packages. The ability to predict this pressure build-up mathematically would be of great value to the canned food industry. The objective of this work was to develop a mathematical model capable of predicting equilibrium head space pressure at retort temperature within a rigid air-tight container filled with various concentrations of the saline solution while undergoing a thermal retort sterilization process under various initial and boundary conditions of temperature, pressure, headspace volume and salt concentration. Experiments were carried out using a wireless temperature and pressure sensor inserted within a rigid pressure vessel containing a saline solution. The vessel was then processed in a retort under various initial and boundary conditions. The mathematical model was built upon earlier models that performed well with pure distilled water, but not with aqueous solutions of dissolved salts or sugars. These earlier models were based on the assumption that pressure build-up was an isentropic process that was likely not valid. The model developed here assumes air in the headspace of a canned food being retorted follows a polytropic process. Experimental results showed that the polytropic exponent (n) is a function of the initial headspace volume and was demonstrated to predict internal head space pressure within 1-2% agreement with experimental results.
E-mail: atex@ufl.edu