Precooking Tuna: A Study of the Factors Impacting the Time Required for Precooking

Precooking tuna is an essential part of the process of manufacturing traditional canned tuna. This paper briefly describes the manufacturing processes for precooking tuna in a conventional atmospheric precooker. Fish thickness and weights were measured to determine thickness variation by fish size. A finite difference simulation model was used to study the impact of three factors (fish size, initial backbone temperatures, and ambient steam temperatures) on precooking times. Results obtained with the simulation model indicate that the factors affecting precooking times are, in decreasing order, fish thickness, initial temperatures, and ambient steam temperatures. A multiple regression analysis indicates that the combination of fish size (thickness) and initial backbone (core) temperatures can account for 95% of the variation in predicted precooking time, with most of the variation based on fish thickness. Suggestions are offered for optimizing recovery of precooked fish and using the End Point Internal Product Temperatures (EPIPT) to control precooking results.