INVESTIGATION OF ANTIOXIDANT ACTIVITY OF PEAT LIPIDS AND SAPROPELS FROM WESTERN SIBERIA
The antioxidant activity of lipids extracted from peats and sapropels from Tomsk and Novosibirsk Regions and Khanty-Mansi Autonomous Okrug is estimated by microcalorimetry. The presence of antioxidants (AO) in the lipids of all peats under study and in a sapropel from the Dolgoye Lake is confirmed by the presence of an induction period (950–14000 s) on the heat release curve and the decrease in the final rate of the model reaction of the initiated cumene oxidation by 25–90%. The total amount of lipid antioxidants varying within the range (22–183)∙10-3 mol/kg is determined by the degree of inhibition of the oxidation reaction. The concentration of identified organic compounds (25–186 μg/g) including alkanes, fatty acids, steroids, terpenoids, and tocopherols is determined by chromatography-mass spectrometry, which correlates with the amount of AO in the peat. It is shown that the samples of initial peats are ordered by their antioxidant activity as follows: sphagnum fuscum > cotton grass > lowland wood > sphagnum phallax. Sphagnum fuscum peats are characterized by the maximum biological activity, which makes it possible to recommend them as an optimal raw material for practical use.