Lipid-Protein Oxidation and In Vitro Digestibility of Fermented Turkey Sausages as Affected by Lipid Formulation

This research investigates the effects of using different lipid formulations (100% beef fat, 85% beef fat+15% olive oil, or 70% beef fat+30% olive oil) in fermented turkey sausages on protein-lipid oxidation, in vitro digestibility, and related quality parameters. The use of olive oil results in decreased fat content, modified fatty acid profile, and increased pH value, acidity, and water activity, besides changes are recorded in instrumental quality and sensory features. Lipid oxidation is higher in samples with 30% olive oil than in the others. Carbonyl content increases depending on oil level and storage time. alpha-aminoadipic semialdehyde is only detected in products containing 30% olive oil and their concentrations increased with storage. gamma-glutamic semialdehyde also increases by olive oil inclusion, but decrements are recorded during storage. Increasing olive oil results in increased pepsin digestibility but losses are recorded in both pepsin and trypsin plus (alpha-chymotrypsin digestion rates during storage.