Optimizing the sterilization process of canned yellowfin tuna through time and temperature combination

Abstract

Differences in can dimension, filled volume and type of sterilization equipment affect the heat penetration rate, temperature and time required for sterilization process in canned food. Thus, careful calculation and decision for those factors are critical to determine the final product quality. Therefore, this research aimed to investigate the quality of canned yellowfin tuna in a specific can dimension using a 24 L pressure canner by applying different time and temperature combination i.e., sterilization at 121°C for 20 minutes and at 115°C for 50 minutes. Two type of mediums used were palm oil and brine. Heat penetration study and calculation of sterilization time (Fo value) were conducted using thermocouple data logger for both methods. The results showed that the protein content decreased slightly from 24.6% (fresh tuna) to 23,57% (canned tuna sterilized at 121°C for 20 min) and to 13,31% for canned tuna sterilized at 115°C for 50 min. There was a sharp increment obtained for fat content of canned tuna in palm oil (0.54% to 10.6%). Heat penetration study indicated that the Fo for canned tuna in brine were longer (30.13 minutes) than tuna in oil (20.09 minutes). This research suggests that sterilization of canned tuna is recommended to be done at 121°C for 20 minutes with regards to the nutritional content of the final product, particularly the protein content.