A highly efficient extraction of plant essential oils using ball mill-assisted hydrodistillation for antibacterial applications

Abstract

Plant essential oil has received considerable scientific interest due to its antibacterial and anti-infective properties. However, the conventional hydrodistillation (HD) method is limited by low extraction efficiency. To solve this problem, this work innovatively introduced ball milling pretreatment technology and integrated it with HD to develop a highly efficient ball milling - assisted hydrodistillation (BMAHD)extraction method. The mechanical force of ball milling can effectively disrupt the cell wall structure of Thymus vulgaris, facilitating a more comprehensive release and outflow of essential oils and intracellular substances. Consequently, the extraction efficiency of subsequent distillation is significantly enhanced. We employed response surface methodology to optimize the process and determined the optimal conditions as follows: a ball milling time of 95 min, a rotation speed of 426 r/min, and a liquid-to-solid ratio of 22 mL/g. Under these conditions, compared with the traditional HD method performed in this study, the extraction yield increased by 34.65%. Gas chromatography-mass spectrometry (GC-MS) analysis revealed 28 identified constituents. Antimicrobial efficacy assays were conducted against Escherichia coli and Staphylococcus aureus, and the results demonstrated that Thymus vulgaris L. essential oil (TVEO) exhibited significant inhibitory effects on both bacterial strains. This research not only offers an innovative and scalable solution for the efficient extraction of essential oils, but also provides a scientific foundation for its potential applications in antimicrobial fields.