Study of oxidative stability of fish oil in different conditions

The oxidation of lipids containing unsaturated fatty acids in their structure represents a large-scale and mul-tifaceted challenge for modern food chemistry and nutrition science. This process is the primary cause of spoilage in fat-containing products, leading to a significant reduction in their biological value and safety. The degradation of key fatty acid molecules, such as oleic, linoleic, and alpha-linolenic acids-characteristic of vegetable oils-as well as long-chain polyunsaturated fatty acids (PUFAs), primarily eicosapentaenoic and docosahexaenoic acids-typical of fish oil, marine hydrobionts, and certain microbiological sources-is examined in detail. Particular attention is paid to the dynamics of the accumulation of volatile organic compounds that form the specific, often unpleasant taste and odor characteristic of rancidity. The initial mechanism of autoxidation, initiated by the formation of free radicals and hydroperoxides, may appear predictable in its early stages. However, as the chemical reactions progress, the processes evolve into a complex cascade of transformations. The composition of the final and intermediate breakdown products, including aldehydes, ketones, alcohols, and furans, is difficult to predict and directly depends on the physicochemical nature of the substrate, as well as on environmental conditions: temperature, oxygen availability, the presence of transition metal ions, and exposure to light. An analysis was conducted on the influence of various heat treatment methods (boiling, frying, pasteurization) on the intensity of destructive processes. It was established that thermal stress not only accelerates primary reactions but also triggers specific peroxide decomposition pathways that are characteristic of high-temperature regimes. To prevent premature oxidative spoilage and preserve the native organoleptic characteristics of oils, the use of a wide range of antioxidants, both synthetic and natural in origin, is substantiated. Current understanding of the pathways for stabilizing lipid systems is systematized, and approaches to optimizing technological processes in the production of functional food products enriched with PUFAs are proposed.