Extraction and investigation of the lipophilic fraction from Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) forestry side-stream biomass

Coniferous forests in the European Union serve as crucial sources of roundwood, as well as contribute to various industries with different wood products. Harvesting of these trees leaves significant amounts of needles and small branches (logging residues). This underutilised forestry side-stream has the potential for various applications in the bioeconomy due to its chemical composition. Extraction of biomass involves various methods and solvents, including petroleum-based solvents, raising environmental and health concerns. This study aims to assess different extraction methods, with a focus on minimising or eliminating the use of hydrocarbon solvents, thereby refining valuable compounds for various applications, as well as evaluating the antimicrobial, antifungal and antioxidant activities of the obtained extracts. The most effective methods in extracting pine and spruce wood logging residues were determined to be maceration at boiling temperature with methanol and butanol, respectively. Extracts consisted of various compound groups such as fatty acids, resin acids, terpenes and more. The obtained extracts demonstrated antimicrobial and antifungal activity, as well as antioxidant activity.