INFLUENCE OF PRESSING PARAMETERS ON THE OXIDATIVE STABILITY OF FLAXSEED OIL

<ns0:p>.Linseed oil is a valuable source of polyunsaturated fatty acids, but its high sensitivity to oxidation makes the stability of the product critically dependent on the technological parameters of pressing. Commercial producers are forced to balance between increasing the yield of oil and preserving its biological value, which necessitates the need for systematic analysis of the influence of temperature, pressure, and type of presses on the quality of the finished product. To summarize scientific data on the influence of mechanical pressing parameters on the oxidative stability of linseed oil and to determine the optimal technological conditions that allow minimizing the degradation of polyunsaturated fatty acids. Analytical, comparative, and structural-logical methods were used. A systematic review of research results on mechanical pressing, cold pressing, and hydraulic technologies was conducted. Special attention was paid to the dependence of peroxide value, acid value, and the rate of primary oxidation initiation on technological modes. It is generalized that increasing the pressing temperature above 40–50 °C significantly accelerates the primary oxidative processes, initiating the destruction of alpha-linolenic acid. It was established that screw presses provide a higher oil yield, but are accompanied by more intense local heating and, accordingly, a decrease in product stability. In contrast, hydraulic pressing allows maintaining a low temperature throughout the process, which contributes to better preservation of polyunsaturated fatty acids, although the oil yield is lower. The design features of the presses were analyzed and the technological parameters that most affect the initial oxidation were established: pressing duration, specific pressure and feed rate of raw materials. Recommendations were formed for manufacturers to optimize technological modes to obtain linseed oil with high oxidative stability. The results can be used in the production of cold-pressed oils, when modernizing pressing equipment and when developing technologies with increased preservation of bioactive components.</ns0:p>