Biorefining fractionation of the Camellia oleifera Abel. hull into diverse bioproducts with a two-stage organosolv extraction

•Biorefining fractionation of tea oil fruit hull (TOFH) into diverse bioproducts.•Two-stage organosolv extraction was of great promise for biorefining of TOFH.•Aqueous ethanol organosolv extraction tended to bioactive components.•Atmospheric glycerol organosolv extraction acted mainly on the fiber structure.

This study developed a two-stage organosolv extraction process for the production of diverse components from tea oil fruit hull (TOFH) - a common lignocellulosic byproduct of tea oil processing industry. Results showed that a mild aqueous ethanol organosolv (AEO) extraction isolated 83.8% of tea saponin and 81.5% of tannin from the TOFH. Further, a severe atmospheric glycerol organosolv (AGO) extraction recovered the residual tea saponin and tannin. Meantime, the AGO process removed 40% of the hemicellulose and 35% of the lignin. The solid residual after the two-stage AEO-AGO extraction had a high cellulose hydrolyzability (>95%), much higher than that (only 40%) of one-step AEO extracted solid residual. Structural features of these undissolved solids were characterized by SEM, AFM and FT-IR. The two-stage organosolv extraction showed good potential in biorefining of the agroforestry biomass into value added bioproducts.

Graphical abstractNote: AEO, aqueous ethanol organosolv; AGO, atmospheric glycerol organosolv.Download high-res image (163KB)Download full-size image