Express method for determination of selected quality indexes of walnut oil using analyzer signals «Electronic nose»

This paper presents the autoxidation process of extra virgin oils. It was established that walnut oil rapidly oxidized due to the prevalence composed of unsaturated fatty acids (90,4%). Theoretically substantiated that the destruction of triglycerides with the accumulation of odorizing substances, oxidation products. This indicates that goes deep oxidation process, which is not accompanied by changes in the organoleptic characteristics. It is not perceptible by biological sensory systems. The paper deals the possibility of using gas analyzer «MAG-8» with methodology «electronic nose» to assess the oxidation rate of walnut oil in terms of composition and content the equilibrium gas phase. Changes in the quantitative and qualitative composition of volatile substances above oil during storage have been analyzed. Express method for determination of peroxide value and acid value using signals of sensors coated with polyethyleneglycol sebacate and dicyclohexano-18-crown-6 has been developed. The authors offer the integral index of oil oxidation level - the area of «visual fingerprint» that be indicative for content of peroxides, acids, alcohols, ketones, esters, and their polymerization products.