14A-37

J. ZHANG, Department of Biological and Agricultural Engineering, North Carolina State University, Box 7625, 137 Weaver Lab, NCSU, Raleigh, NC 27695, B. E. Farkas, Food Science, North Carolina State University, 129 Schaub Hall Box 7624, Raleigh, NC 27695, and S. A. Hale, Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695.

JUSTIFICATION: The commercial canned tuna industry is the largest processor of fish in the world with single manufacturing facilities using up to 1000 tons raw product per day. Precooking and cooling are two critical thermal processes in which protein denaturation and enzyme activity occur which impact yield and quality of the final canned tuna product. Processing technologies have remained largely unchanged for over fifty years. Therefore, process optimization through the use of numerical simulation has great potential to lead to improvements in throughput, efficiency, and product quality for these applications.

OBJECTIVE: The goal of this research was to develop a numerical simulation of the tuna precooking and cooling process to aid in improvement of these critical thermal processing steps.

METHODS: The finite element method (FEM) was used to study the tuna precooking and cooling process. A two dimensional model consisting of three regions, muscle, backbone and viscera was developed to study these two processes. Prior research on thermal properties of skipjack tuna was applied in the model. Preprocessor and finite element software were used for solution of the problem.

RESULTS: The validity of the model was tested via comparison with experimental data collected at a commercial processing facility. The temperature profile from FEM model showed that the differences in physical and thermal properties in skipjack tuna do not affect internal temperature profiles during heating and cooling. Various processing conditions have different impacts on fish heating and cooling rates and process efficacy.

SIGNIFICANCE: The finite element method was shown to be a very powerful tool in the analysis of skipjack thermal processing. This mathematical model will aid in finding the optimum conditions for each process, reducing yield loss, and improving product quality. Kinetic data such as protein degradation and enzyme activity may be applied to this model allowing processing conditions and product interactions to be studied.