Aspects of primary chaga raw material sorting (Inonotus obliquus f. sterilis)

In this study, we investigated five non-homogenized chaga raw material samples collected from different regions of the Pskov Region (Russia) and one homogenized sample (in powder form) from the Republic of Serbia. Macroscopic analysis of the four raw material samples allowed for clear differentiation of the crustal zone, medullary region, and mycelial pulp. Micromorphological analysis of all six raw material samples correlated with the aforementioned macroscopic differentiation of the chaga outgrowths and allowed for the identification of diagnostically significant microstructures. For raw material obtained from the crustal zone, brownish-stained hyphal clusters of prosenchymatous texture are diagnostically significant. For raw material from the medullary region of the outgrowth, a more open arrangement of hyphae and the presence of pleurocetes are characteristic. The results of the morphometric analysis allowed for the expansion of the diagnosis of I. obliquus f. sterilis. It was shown that for the intake of aqueous extracts of the fungus for prophylactic purposes, preliminary sorting of raw material parts is not necessary, since different fractions are characterized by different contents of extractable biologically active substances (crust – betulinic acid predominates, medullary region of the outgrowths – β-glucans and melanins, mycelial pulp – inotodiol). For pharmaceutical productions requiring alcohol extraction and subsequent purification of products, on the contrary, it is recommended to carry out preliminary sorting and preparation before drying the raw material. Furthermore, the elemental composition of the chaga raw material samples was determined by X-ray spectral microanalysis based on comparative analysis using the modern analytical method of scanning electron microscopy using a KYKY-EM8000F STD FEG SEM microscope (China) under high vacuum conditions. To assess the elemental composition of the samples, an energy-dispersive microanalysis system (AZtec, Oxford Instruments) was used. Before analysis, the sample was coated with a thin conductive layer of carbon (13 nm) using a Nano-Structured Coating Co vacuum sputtering system (Iran). Thus, the goal of this work – morphometric analysis of various parts of fungal chaga raw material with the assessment of the possibilities of its primary sorting depending on the purposes of further use – was achieved, and the results of the study allowed us to propose aspects of differentiation of chaga raw material during its primary sorting for further use in pharmaceuticals and the production of biologically active additives.