Nanoemulsion Formulation of Black Pepper Essential Oil Using the Emulsion Phase Inversion Method: Assessment of Antibacterial Activity. -

Nanoemulsion Formulation of Black Pepper Essential Oil Using the Emulsion Phase Inversion Method: Assessment of Antibacterial Activity.

This study explores the potential of Vietnamese black pepper essential oil (BPEO) in nanoemulsion form, prepared via the Emulsion Phase Inversion method, for its antibacterial activity against various food pathogens. BPEO, known for its bioactivities, particularly against common foodborne bacteria, is investigated for its application as a preservative in meat products. Nanoemulsions offer enhanced bioactivity in water-rich environments, making them promising for food preservation. The study aims to leverage the advantages of a low-energy method for formulating BPEO nanoemulsions, emphasizing cost-effectiveness and scalability.

Materials and Methods:

Materials and Chemicals: Vietnamese black pepper essential oil (BPEO), Tetrazolium Chloride (TTC), Dimethyl sulfoxide (DMSO), polyoxyethylene sorbitan monooleate (Tween 80), and Amoxicillin were obtained from various suppliers.

Nanoemulsion Formulation: BPEO nanoemulsion was prepared using the Emulsion Phase Inversion method, involving the mixing of BPEO, Tween 80, and distilled water, followed by stabilization and storage.

Determination of Volatile Compounds: Gas Chromatography-Mass Spectrometry (GC-MS) was employed to identify compounds in BPEO and nanoemulsions.

Droplet Size and Polydispersity Index: Dynamic Light Scattering with HORIBA SZ 100 Nanoparticle Analyzer was used to determine mean droplet size and polydispersity index.

Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC): Antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, and Staphylococcus aureus was assessed through MIC and MBC determination by the dilution method.

Antibacterial Activity on Meat: BPEO nanoemulsion’s antibacterial effect on pork infected by bacteria was examined, evaluating bacterial population over time.

Meat Preservation: Minced beef, lean pork, and chicken were preserved with BPEO nanoemulsion at different concentrations, assessing total aerobic microbial count during storage.

Result and Summary: In this study, a stable black pepper essential oil (BPEO) nanoemulsion was successfully formulated using the Emulsion Phase Inversion (EPI) method and demonstrated efficacy for at least 6 months. The nanoemulsion exhibited higher antibacterial activity against food pathogens compared to free BPEO, with Escherichia coli and Salmonella enterica being particularly sensitive. This nanoemulsion also effectively inhibited bacterial growth on meat samples infected by E. coli and S. enterica. Notably, as a meat preservative, the nanoemulsion significantly reduced total aerobic microbial growth in the samples stored at 5°C.

The advantages of the formulated nanoemulsion include its small droplet size (18 nm) and long-term stability, addressing challenges associated with lipophilic essential oils. Despite a slight increase in polydispersity index over time, the concentrations of key components in BPEO remained consistent in the nanoemulsion phase. The study highlighted the potential of BPEO nanoemulsion, emphasizing its superior antibacterial effects and its application as an effective meat preservative. The findings contribute to the understanding of essential oil nanoemulsions for food preservation.

Reference:

HIEN, L.T.M. AND DAO, D.T.A., 2022. Antibacterial activity of black pepper essential oil nanoemulsion formulated by emulsion phase inversion method. Current Research in Nutrition and Food Science Journal, 10(1), pp.311-320.