Cinnamomum camphora fruit peel as a source of essential oil extracted using the solvent-free microwave-assisted method compared with conventional hydrodistillation

In the present study, essential oil from Cinnamomum camphora fruit peel was first separated and characterized by GC-MS. Solvent-free microwave-assisted extraction (SFME) was performed to isolate the essential oil, and the extraction procedure was optimized using a Box-Behnken design. The optimum SFME conditions yielded 80.35 +/- 1.88 mg/g of essential oil with 76% moisture content, using a microwave irradiation power of 420 W and an irradiation time of 22 min. No obvious difference was observed between physical constants of essential oil extracted by SFME and hydrodistillation (HD). Scanning electron microscopy micrographs demonstrated more disruption of C. camphora fruit peel cells treated with SFME than by conventional HD. SFME was proposed as an energy-saving, high-efficiency, and environmentally friendly method, as evidenced by its higher yield and volumetric mass transfer coefficient, larger proportions of oxygen compounds, lower consumption of electricity, and lower amounts of CO2 release and water waste compared to conventional HD. The results show that a once discarded part of C. camphora can be utilized as a source for the production of essential oil.