Efficient Extraction, Chemical Characterization, and Bioactivity of Essential Oil From Pine Needles

Pine needles are a rich source of bioactive compounds, and there are few reports on the extraction and identification of active substances in various types of pine needles.

The objective of this study is to enhance the efficiency and yield of pine needle essential oil extraction by employing an innovative ultrasonic-assisted salt-out hydrodistillation technology. It also aims to establish a correlation between gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) to distinguish essential oils from Cedrus deodara, Pinus thunbergii, Pinus massoniana, and Pinus koraiensis.

Optimal extraction conditions will be determined through dynamic curve fitting and response surface analysis. Essential oils will be analyzed by E-nose and GC-MS coupled with chemometrics. Radical-scavenging effects on ·OH, DPPH·, ABTS⁺ radicals, and antibacterial activity against Escherichia coli and Staphylococcus aureus will be evaluated.

Optimal extraction conditions were 100 min of distillation, 7.762% sodium chloride, 9.596-mL/g liquid material ratio, and 170.155-W ultrasonic power. Essential oil yields were 0.144%, 0.214%, 0.425%, and 0.852% for C. deodara, P. thunbergii, P. massoniana, and P. koraiensis, respectively. GC-MS identified 74 volatile components. PLS-DA revealed nine key compounds, including α-Myrcene, α-Pinene, α-Phellandrene, Limonene, Caryophyllene, Bornyl acetate, β-Pinene, Germacrene D, and Camphene. PCA of E-nose and GC-MS data highlighted sample differences. All essential oils exhibited antioxidant and antibacterial activities, linked to α-pinene, β-Pinene, and Germacrene D.

This study introduces efficient methods for efficient extraction and characterization of pine needle essential oils, providing a foundation for bioactive applications and enhancing product quality and global innovation in the industry.