Isolation Of Volatils From Maritime Pine Sawdust Waste By Different Processes: Ultrasound, Microwave, Turbohydrodistillation, And Hydrodistillation

This study concerns the transformation of maritime pine ( Pinus pinaster) sawdust waste into potentially novel products through isolation of volatile compounds in the form of valuable oil. Different techniques, namely, turbohydrodistillation (THD), solvent-free microwave extraction (SFME), microwave hydrodiffusion and gravity (MHG), and ultrasound-assisted extraction (UAE) were tested. These different processes were compared to conventional hydrodistillation (HD) and allowed to extract almost similar yields of isolated oils. THD which consists in a permanent agitation during extraction and UAE improve the kinetics of extraction, but MHG and SFME required the shortest extraction times, 60 min to reach a maximal yield of 0.272 and 0.266% (w/w), respectively. The compositions of isolated oils are almost similar with a high proportion of oxygenated compounds for MHG and SFME, respectively, 56.9% and 54.5% compared with 37.7%, 44.1% and 34.1%, respectively, for THD, UAE, and for the conventional HD method.