Role of wood macromolecules on selective sorption of phenolic compounds by wood

Wood is a complex structure of various macromolecules, mainly cellulose, hemicellulose, and lignin. Although the sorption process of some organic compounds by wood has been elucidated, the relative contribution of its different fractions in the sorption mechanism is not clearly determined. Certain works predict the amount of organic compounds sorbed on wood as a direct relationship to its lignin fraction. All wood macromolecules, however, seem to have the capacity to sorb organic compounds. Sorption of phenolic compounds on individual wood macromolecules has been studied and compared to that on wood. Wood-water partition coefficients ( K wood) for phenolic volatiles and their sorption rates in the presence of lignin display a linear relationship. Results show that cellulose and hemicellulose sorb all phenolic compounds without apparent distinction, whereas lignin is a selective sorbent of these compounds. Sorbant availability and sorbate chemical structure seem to be the key factors governing the sorption mechanism. Sorption kinetics study gives apparent diffusion coefficient values of aroma compounds, bringing new kinetic data for understanding the ternary system of wood, hydroalcoholic solution, and phenolic compounds.