Selected quality properties of lipid fraction and oxidative stability of dry dog foods under typical storage conditions

Selected quality and oxidative stability parameters of the lipid fraction were analyzed in four complete dry dog foods with different main animal-derived ingredients. The measurements were taken at the time of bag opening and repeated after 7 months of continuous storage in normal room conditions. Fatty acid (FA) content and acid value (AV) were determined, followed by subsequent pressure differential scanning calorimetry (PDSC) measurements. From the resulting PDSC exotherms, maximum induction time (tau (max)) was determined and used for assessing the oxidative stability. The study revealed changes in lipid quality and oxidative stability of dry dog foods that appeared during storage. Results of FA and AV assays showed specificity and marked quality differences of lipid ingredients declared as used in the production process. Product with the lowest content of polyunsaturated FA had the highest oxidative stability. PDSC appeared to be an effective method for the analysis of lipid oxidation in pet foods.