Thermodynamic study of canned mince meat and fish in metal cans during 30 months storage

Department of Analytical and Physical chemistry, University of Food technologies, 4002 Plovdiv, Bulgaria

^* Corresponding author: gandova_71@abv.bg

Abstract

Long storage period for the meat and fish cans of 30 months was presented. The provide investigation aims to found thermodynamic stability in mackerel in tomato sauce and finely ground pork minced meat. During the storage period a decrease in pH in two types of cans were seen. pH values for mackerel in tomato sauce and for finely ground pork minced meat cans were measured between 6.2±0.19 to 4.8±0.22 and 5.8 ±0.24 to 3.9±0.17 in the starting to the end of storage, respectively. Determined absorption is used to calculated equilibrium constant, Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS). For mackerel in tomato sauce ΔG exhibit value -8.33±0.07 kJ.mol⁻¹ and for finely ground pork -6.79±0.09 kJ.mol⁻¹. Microscopic examinations were performed and the size of the particles was determined. In measurements in mackerel in tomato sauce the sizes are between 25±0.79 to 62±1.28 μm and for finely ground pork minced meat the particle sizes are between 32±1.12 to 89±2.48 μm in the investigation period. Based on the experiment, both types of canned food are defined as thermodynamically stable after negative Gibbs energies observations, but canned fish is defined as more stable and may have a longer stored.