Ultrasound-assisted preparation of anise extract nanoemulsion and its bioactivity against different pathogenic bacteria.

The present work aimed to characterize the nanoemulsion of anise seed extract and to compare its efficacy with the bulk extract against pathogenic bacteria. The anise seeds extract was prepared by cold solvent extraction method using ethanol. Nanoemulsion of anise extract was formulated using ultrasound assisted method and analyzed using high-performance liquid chromatography (HPLC), fourier transform infrared spectroscopy (FTIR) and UV-visible spectrophotometry. The antimicrobial activity of the nanoemulsion was tested against seven foodborne pathogenic bacterial species. Results showed that the extract contained anethole (37%), naringenin (21%), and taxifolin (13%) as the major phytochemical components. The average droplet size of the nanoemulsion droplets was measured by dynamic light scattering (DLS) and confirmed by transmission electron microscope to be about 400 nm. Anise extract nanoemulsion showed higher antimicrobial activity against most of the tested pathogens. Anise extract nanoemulsion performed better than bulk extract as an antimicrobial agent against some foodborne pathogenic bacteria.