Identification of the oxidation and hydrolysis products content influence on the rapeseed oil oxidation induction period

Abstract

The object of the study is the dependence of the induction period of rapeseed oil on the content of oxidation and hydrolysis products. A feature of the work is determining the approximation dependence of the induction period of accelerated oxidation of refined rapeseed oil on the content of primary oxidation products and free fatty acids. This is useful when predicting the shelf life of refined rapeseed oil. It was determined that both factors negatively affect the oxidation stability of refined rapeseed oil. An increase in the peroxide value decreases the induction period of model oil samples by 32.8512 units for each additional mmol ½ O/kg. In turn, increasing the acid value of oil samples reduces the induction period by 19.8424 units for each additional mg KOH/g. Different oxidation dynamics of model samples of refined rapeseed oil with tocopherol were revealed, depending on the concentration of primary oxidation and hydrolysis products. The obtained data are explained by the fact that the primary lipid oxidation products are unstable and quickly decompose to form free radicals. These radicals initiate further lipid oxidation, resulting in reduced oil quality. In addition, free fatty acids are more reactive than triglycerides and are more easily oxidized. A feature of the obtained results is the possibility of modeling processes that affect the oxidation stability of refined rapeseed oil. From a practical point of view, the research results allow initiating measures to maintain the safety of oil-containing food products based on refined rapeseed oil. An applied aspect of using the scientific results is the possibility of rationalizing the storage conditions of refined rapeseed oil to maximize its shelf life and increase competitiveness.