Virtual Simulation of Temperature Distribution throughout Beef Packages with Time-temperature Indicator (TTI) Labels

If the time-temperature indicator (TTI) experienced a different temperature than the accompanied packaged food, influenced by heat transfer between the TTI, package, and ambient air, TTI would incorrectly predict the food quality changes with temperature. Temperature distributions of a finite slab with different sizes, representing beef packaged with TTI, were estimated by the finite element method (FEM). The thermal properties of the beef and TTI, such as heat capacity, density, and heat conductivity, were estimated from the relevant equations using their chemical compositions. The FEM simulations were performed for three cases: different locations of TTIs on the beef, different thicknesses of beef, and non-isothermal conditions of ambient air. The TTIs were mounted in four different locations on the beef. There was little difference in temperature between four locations of the TTI on the package surface. As the thickness of the slab increased, the temperature of the TTI changed faster, followed by the corner surface, as well as middle and bottom parts, indicating the possible error for temperature agreement between the TTI and the slab. Consequently, it was found that any place on the package could be selected for TTI attachment, but the package size should carefully be determined within a tolerable error of temperature.