Pine Needle of Pinus koraiensis (Siebold & Zucc) Essential Oil Through Liquid Nitrogen Quick‐Freezing Assisted Solvent‐Free Microwave Extraction Process for Antibacterial Application

Abstract

IntroductionThis study investigates the composition and antibacterial properties of essential oil extracted from Pinus koraiensis (Siebold & Zucc) pine needles using a liquid nitrogen freezing treatment combined with solvent‐free microwave extraction (LNSFM).ObjectiveThe aim is to develop a low‐energy, high‐efficiency extraction method for conifer essential oils, analyze their chemical composition, and evaluate their antibacterial efficacy.MethodologyPine needle samples were frozen with liquid nitrogen and subsequently crushed. The essential oil was extracted using solvent‐free microwave technology. A single‐factor test and response surface methodology were employed to optimize extraction parameters. The extraction efficiency of LNSFM was compared with traditional methods through kinetics, and the essential oil components were analyzed using gas chromatography–mass spectrometry (GC–MS). The antibacterial activity of the extracted volatile oil was tested against Escherichia coli and Staphylococcus aureus.ConclusionLNSFM proves to be a green and efficient extraction method suitable for obtaining volatile oils from pine needles, which demonstrate significant antibacterial properties.