Abstract: Low transition temperature mixtures (LTTMs) or solvents are provided that can be used in methods and systems to dissolve and bydrolyze certain components from lignin-containing biomass (e.g., lignin) at mild conditions so that further degradation is prevented. The solvents, methods and systems according to the invention have various advantages over prior technology or approaches. For example, LTTMs are cheap solvents, renewable and/or non-toxic food ingredients. LTTMs dissolve lignin selectively from a lignin-containing biomass. A highly efficient (up to 90%) lignin recovery can be achieved. The recovered lignin is of higher quality. The remaining cellulose is also of higher. Much less water is needed, which means a tremendous reduction of the energy requirement in the recovery process, i.e. less energy needed for evaporating large quantities of water.