Advances in organosolv modified components occurring during the organosolv pretreatment of lignocellulosic biomass

•Organosolv modification is helpful to valorize the OP process.•Organosolv modified products involve lignin phenolics and glycosidic compounds.•Organosolv modification conforms to the lignin-first concept via group-protection.•Trans-glycosylation contributes to the formation of organosolv glycosides.•Co-production of modified products and hydrolysable substrates is desirable for OP.