Chemical composition and bioactivity of hemp, reed canary grass and common reed grown on boreal marginal lands

Abstract

<p>Underutilised agricultural land and former peat production areas in northern Europe are potentially suitable for growing lignocellulosic biomass that could be used in various non-food applications. In this study, the biorefining process of <em>Phalaris arundinacea</em> (reed canary grass), <em>Phragmites australis</em> (common reed), and <em>Cannabis sativa</em> (oil and fibre hemp cultivars) was assessed based on their chemical composition and biological activity using various analytical techniques. Two-stage accelerated solvent extraction was used first with hexane, followed by EtOH/H₂O (95/5, v/v) to extract the lipophilic and hydrophilic fractions of the samples collected during and after the growing season. Later, pressurised hot water extraction (PHWE) and two-stage extraction were performed to examine the biorefinery potential of aqueous extracts focusing on extraction efficiency, quality, and chemical composition of the plant materials. Combining two-stage and elevated extraction temperatures with PHWE resulted in high levels of total dissolved solids (TDS), carbohydrates, phenolics, and bioactivities. Data showed that TDS yielded over 400 mg g⁻¹ for summer oil hemp and approximately 300 mg g⁻¹ for reed canary grass and common reed. Summer-harvested plants had carbohydrate yields of 110–155 mg g⁻¹, while autumn yields were 40–60 mg g⁻¹ for hemp and 120–170 mg g⁻¹ for reed canary grass and common reed, respectively. The findings suggest that aboveground biomass from marginal lands holds potential as a valuable source of bioactive compounds for biorefinery feedstocks, thereby presenting new opportunities for sustainable biomass-based valorisation and future optimisation of two-stage extraction methods targeting hemicellulose-rich fractions.</p>