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

Introduction: 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.

Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: 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.