Abstract
Ensuring oxidative stability is essential for maintaining the sensory quality, safety, and shelf life of meat products. Oxidation alters flavour, colour, and texture, while producing reactive compounds that accelerate spoilage, compromise nutrition, and reduce consumer acceptance. Traditional assays, although widely used, present several limitations. They rely heavily on endpoint measurements, lack real-time monitoring capability, and often fail to capture the dynamic behaviour of fats within complex meat matrices. These shortcomings highlight the need for methodological advances that can accurately characterize oxidation kinetics. To address these challenges, this thesis introduces a kinetic-based framework centered on isothermal calorimetry. This method continuously measures the heat released during lipid autoxidation and converts it into oxygen consumption profiles, offering dynamic, real-time insights into the oxidation process. By employing controlled radical initiation with azo-compounds, the approach generated reproducible conditions for calculating key parameters such as the propagation rate constant, oxidizability index, and antioxidant efficiency. Unlike conventional assays, which provide fragmented or indirect information, isothermal calorimetry captured initiation, propagation, and inhibition phases in detail, establishing a robust platform for studying lipid oxidation in complex food systems. The method has been then applied to evaluate the efficiency of natural antioxidants as potential clean label alternatives to synthetic compounds to inhibit lipid oxidation of meat. In detail, ultrasound assisted extracts of Salvia officinalis (sage) and Origanum vulgare (oregano) were incorporated into speck fat, a traditional dry-cured ham product of South Tyrol . Their antioxidant efficiency was compared to the one of synthetic antioxidants such as tert-butylhydroquinone (TBHQ), propyl gallate, and catechol. Results revealed that oregano extract achieved antioxidant efficiency values comparable to those of synthetic antioxidants, while sage displayed concentration-dependent effects, with higher levels significantly extending induction times. Phytochemical analysis confirmed that phenolic compounds, including rosmarinic, salvianolic, and carnosic acids, were the main contributors to the observed protective effects. These findings not only validate the potential of natural extracts as effective stabilizers but also provide mechanistic insight into their modes of action. Overall, the outcomes of this PhD research establish a coherent narrative: identifying the limitations of conventional oxidation studies, developing a kinetic methodology to overcome them, and applying the method to demonstrate the viability of natural antioxidants in real food matrices. The work advances fundamental science by refining the mechanistic understanding of lipid oxidation, while also offering practical tools for industry by presenting plant-based alternatives that meet consumer demand for natural preservation strategies. In summary, this thesis enhances oxidative stability research through the integration of real-time calorimetric monitoring, kinetic modelling, and antioxidant evaluation. It demonstrates that isothermal calorimetry provides a powerful and versatile platform for oxidation studies and that natural extracts such as oregano and sage can effectively replace synthetic antioxidants in meat systems. By bridging mechanistic discovery with applied solutions, the research offers a roadmap for extending shelf life, reducing waste, and delivering high-quality products aligned with clean-label and sustainability goals. Ultimately, this work lays the foundation for next-generation preservation strategies that combine natural antioxidants, real-time monitoring, and intelligent processing to ensure sustainable and consumer-trusted meat production.