Utilization of By-Product from Pomelo (Citrus maxima Burm. Merr.) as Raw Materials to Produce Essential Oil by Steam Distillation Method

Pomelo (Citrus maxima Burm. Merr.) is a fruit tree widely cultivated in the Mekong Delta, Vietnam. Diversifying products from various components of pomelo fruit, particularly by effectively treating by-products, presents a promising opportunity to create a strong brand for products derived from Citrus maxima. Essential oils, which are volatile aromatic compounds, hold the highest economic value among the various components of the plant. In this study, the extraction of pomelo essential oil (EO) was carried out using the steam distillation method on a 500 kg/batch device, achieving a high yield of 0.87% within 2 hours after the first amount of EO was obtained. D-Limonene was identified as the main compound, accounting for 89.106% to 94.422%, along with other compounds such as α-pinene, sabinene, β-mycrene, α-phellandrene, σ-cymene, β-ocimene, γ-terpinene, β-caryophyllene, and β-copaene, as determined by GC-MS analysis. EOs are colorless and liquid, with a scent characteristic of pomelo peel in all samples. Other physicochemical properties of Eos were also evaluated in this study, including density, metal content, refractive index, and polar rotation angle. The density of the EOs ranged from 0.8430 to 0.8440, the metal content present in the EO was < 2 ppm, the refractive index at 20°C reached 1.4724 to 1.4728, and the polar rotation angle at 20°C ranged from +87.00 to +89.90. These findings indicate that the pomelo peel obtained from young pomelos during the development stage after production and processing could serve as an abundant, stable, and cost-effective source of local raw materials.