OPTIMIZATION OF PECTIN EXTRACTION FROM THE BARK OF SIBERIAN FIR (ABIES SIBÍRICA), CORRUPTED BY USSURI POLYGRAPH (POLYGRAPHUS PROXIMUS)

Species of Abies trees are considered susceptible to the effects of diseases and pests. As a result of the complex biotic impact of the Ussuri Polygraph (Polygraphus proximus Blandford) the area of potential drying of Siberian fir (Abies sibirica Ledeb) stands up to 10 million hectares. Trees corrupted by root pathogens are a center of desiccation, from where pathological decay spreads, so also there arise an urgent issue of disposal of corrupted bark and wood waste. A promising solution to this problem is the extractive processing of wood-bark wastes aimed to obtain a wide range of high-valued substances. Fractions of resinous substances, tannins and pectins were isolated from the corrupted A. sibirica bark using the sequential extraction method. The optimization of the process of pectin extraction - one of the most valuable secondary extractive components was carried out. The optimal experimental conditions were established with the highest yield of pectins up to 8.4 wt.%, which is achieved by treating the A. sibirica bark, corrupted by P. proximus, with a HCl solution at pH = 1.71 and the process duration 48 min. The isolated extractive substances (tannins, pectins) from the A. sibirica bark characterized by IR spectroscopy and gel permeation chromatography. The antioxidant activity of tannins and pectins studied using compounds imitated free radicals (1,1-diphenyl-2-picrylhydrazyl), which amounted to 97% and 89%, respectively.