Formulation optimization, antimicrobial mechanisms, and application of Amomum tsao-ko essential oil nanoemulsion

This study aimed to develop a nanoemulsion based on Amomum tsao-ko Crevost et Lemaire (A. tsao-ko) essential oils (EOs) with enhanced packaging properties. A. tsao-ko was extracted using steam distillation, yielding approximately 42 main compounds, with cineolol as the most abundant (41.49 %). The optimal preparation process for the nanoemulsion (ATEON) was determined using response surface methodology (RSM). Disk diffusion assays confirmed that ATEON exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus, with inhibition zone diameters of 1.12 ± 0.07 cm and 1.22 ± 0.17 cm, respectively. The antibacterial properties of ATEON can be due to its ability to disrupt bacterial cell membrane integrity, damage cell walls, and alter cell surface hydrophobicity. Additionally, preservation experiments demonstrated that chitosan (CS) film supplemented with ATEON more effectively preserved pork quality and extended shelf life than CS film alone. In conclusion, ATEON presents a promising active packaging material for fresh meat preservation.