Optimization of grinding and distillation parameters affecting yield and composition of essential oils from the hybrid Eucalyptus grandis × E. camaldulensis (clone 2414)

This study examines how grinding and distillation duration affect the yield and composition of essential oils (EOs) from the natural hybrid Eucalyptus grandis × E. camaldulensis (clone 2414) and its parental species. Hydrodistillation was performed for 2–4 h on ground and whole leaves. Grinding increased yield by 20–25 %, and the optimum extraction time was 3 h. Yields ranged from 1.5 % (E. grandis) to 2.3 % (E. camaldulensis), with 1,8-cineole (42–61 %) as the main constituent. The hybrid exhibited a stable and distinctive chemical profile rich in oxygenated monoterpenes, demonstrating its industrial potential. Leaves were subjected to hydrodistillation using a Clevenger type apparatus under two conditions: ground versus whole leaves, and varying distillation times (2, 3, and 4 hours). EO yields were calculated relative to dry leaf mass, and the chemical profile was determined by gas chromatography–mass spectrometry (GC–MS). Results revealed that grinding significantly enhanced oil recovery, with ground leaves yielding up to 20–25% more oil compared to whole leaves. Distillation time strongly influenced EO output, with an optimal recovery observed at 3 hours; beyond this, additional distillation produced negligible increases. Overall yields ranged from 1.5% (E. grandis) to 2.1% (E. camaldulensis), while clone 2414 consistently displayed intermediate productivity (≈1.8%) that improved under optimized grinding and distillation conditions. GC–MS analysis confirmed 1,8 cineole as the dominant constituent (42–61%), accompanied by α-pinene, p-cymene, and limonene in variable proportions. Notably, the hybrid exhibited a distinctive chemical fingerprint enriched in oxygenated monoterpenes compared with its parents. These findings demonstrate that essential oil yield and composition are strongly influenced by both genetic background and processing variables. Clone 2414 consistently delivered stable and enhanced oil profiles under optimized conditions, highlighting its value as a versatile resource for industrial essential oil production.