Oxidation kinetics of fats from meat and meat products by isothermal calorimetry

Lipid oxidation significantly affects the nutritional value and sensory properties of processed meat products. This study aimed to apply isothermal calorimetry to analyze the oxidation kinetics of fats from chicken, pork, lamb and speck at 40 °C in presence of 2,2'-Azobis(2-methylpropionitrile) (AIBN) radical initiator. Isothermal calorimetry allowed for continuous monitoring of the heat flow developed during the oxidation reaction determining key kinetic parameters such as the induction time (τ), rates of inhibited (R_inh) and uninhibited (R_uni) periods, and oxidizability index (O.I.). The calorimetric data were validated using oximetry and peroxide value measurements (R² = 0.99). Chicken fat exhibited longest τ followed by pork > speck > lamb. The results correlated with the concentration of antioxidants, mainly tocopherols, present in the samples. Furthermore, the O.I. of the fat samples varied significantly (p < 0.05) due to the different fatty acid compositions. Overall, isothermal calorimetry provided valuable kinetic insights while enabling the simultaneous analysis of multiple samples.