Insights into the Composition and Antibacterial Activity of Amomum tsao-ko Essential Oils from Different Regions Based on GC-MS and GC-IMS

Chemical components are one of the most significant traits and attributes of plant tissues, and lead to their different functions. In this study, the composition of Amomun tsao-ko essential oils (AEOs) from different regions was first determined by a combination of gas chromatography-mass spectrometry (GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS). In total, 141 compounds were identified, of which terpenes and aldehydes were the main groups. Orthogonal partial least square discriminant analysis (OPLS-DA) distinguished the samples from different regions clearly, and the main differences were terpenes, aldehydes, and esters. Meanwhile, AEOs showed strong antibacterial activity against Staphylococcus aureus (S. aureus), and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) reached 0.20 mg/mL and 0.39-0.78 mg/mL, respectively. From correlation analysis, 1,8-cineole, (E)-dec-2-enal, citral, alpha-pinene, and alpha-terpineol were determined to be the potential antibacterial compounds. This study provides the basis for the variety optimization of A. tsao-ko and its application as a natural food preservative.