Bioactive compounds extraction from forestry residues using ionic liquids with emphasis on solvents recycling

Carried out the (polyphenol nature) investigations regarding to characterization of the plant biomass processing by-products, using fractionation, namely, treatment with ionic liquids (ILs), using conventional and microwave assisted extraction (MAE). The suitability of ionic liquids (different imidazolium based ILs) for the fractionation of grey alder bark (Alnus incana) in comparison with organic solvents has been evaluated and the potential of the obtained fractions as antioxidants has been determined. The results of the study have shown that, using the select "antisolvents", it is possible to separate the carbohydrate fraction of the polyphenol fraction with a fairly high selectivity. The work shows the whole chain of analytical process performed, from sampling to full analysis, emphasizing the evaluation of the effect of the extraction process on the target polyphenol compounds, their composition and antioxidant activity. The solid phase extraction allows an effective increase in the compounds' recoverability from the IL dissolved part, which cannot be re-extracted with "antisolvents", and allows the recovery of ionic liquid, which is a problematic issue in biomass processing with ionic liquids in the world. In addition, the analytical process integrates sustainable development, which reduces the use of toxic and hazardous substances in extraction processes, replacing them with more environmentally friendly ones.