Process optimization for Pilot-Scale Hydrodistillation of essential oils from Immature Citrus aurantium fruits

This study aimed to optimize the extraction process of essential oil from immature Citrus aurantium fruits to achieve maximal yield. Vegetal material was collected from Morocco's northwestern region during May and June 2023. A pilot-scale hydrodistillation method was employed, and extraction conditions were optimized using the Box–Behnken response surface methodology. The extraction process was monitored until equilibrium or the water was exhausted, and yield optimization was quantitatively evaluated. The optimal result was obtained with the ratio of 1:9.35 under the following conditions: extraction time of 270 minutes, temperature of 130°C, and powder particle size of ≤ 500 μm. 13.48 g of C. aurantium essential oil was obtained, equivalent to a yield of 1.753%. GC-MS analyzed the components of the essential oil. Sixteen different components were detected, accounting for 99.63% of the total essential oil, with two fractions of non-oxygenated and oxygenated terpenes, 86.46% and 13.17%, respectively. Limonene (77.91%) and linalool (9.08%) were predominant components. The linalool content was higher than the values reported in the literature for this cultivar and comparable to the essential oil yield obtained from other common Citrus species. The described method provides a simple and cost-effective approach for extracting bitter orange essential oil for industrial applications