*2.2. Autohydrolysis of Hazelnut Shells*

HS autohydrolysis was performed in a stirred 600 mL stainless steel reactor (Parr Instrument Company, Moline, IL, USA). HS were mixed with distilled water at a liquid to solid ratio (LSR) of 10 g/g of dry HS, heated up to 210 ◦C, and cooled immediately. Heating profiles previously reported for non-isothermal autohydrolysis shown the reaction time to reach the target temperature. Then, heating up from 60 ◦C to 210 ◦C lasted 16 min. These conditions were reported as optimal in literature [10,23]. The autohydrolyzed solids (AS) were separated by vacuum filtration, washed with distilled water, and air-dried before chemical characterization and solid yield determination. The autohydrolysis liquors (AL) were assayed for composition as described in Section 2.5.
