Process optimization for high-content 2-methoxycinnamaldehyde cinnamon essential oil: Combined low-temperature continuous phase-transition extraction and molecular distillation techniques

The increasing demand for high-quality essential oils highlights the need for efficient and sustainable extraction methods. This study presents a novel low-temperature continuous phase-transition extraction combined with molecular distillation (LCPEMD) for cinnamon essential oils (CEOs). The optimal parameters for LCPE were 50 °C, 80 min, 0.5 MPa, and a separation temperature of 65 °C, while molecular distillation was conducted at 60 °C and 40 Pa. Compared to steam distillation (0.653 ± 0.046 %, 6 h), LCPEMD (0.884 ± 0.028 %, 2 h) and LCPESD (0.840 ± 0.027 %, 3.5 h) demonstrated higher extraction efficiency. LCPEMD also yielded the highest levels of key compounds, including 3.15 % coumarin and 11.62 % 2-methoxycinnamaldehyde, with strong antioxidant activity, meeting Chinese quality standards. Furthermore, by-products from LCPEMD can be further utilized, improving overall cinnamon utilization. LCPEMD offers a novel, rapid, and high-quality method for essential oil extraction, applicable to various spice crops. • Optimized process achieves rapid and high-yield extraction of cinnamon oil. • Process increases coumarin and 2-methoxycinnamaldehyde contents. • Process enhances the antioxidant activity of cinnamon essential oil. • Process outperforms traditional steam distillation in efficiency and quality.