Enhancing the antimicrobial activity of d-limonene nanoemulsion with the inclusion of ε-polylysine

Food Chem. 2017 Apr 15;221:18-23. doi: 10.1016/j.foodchem.2016.10.037. Epub 2016 Oct 11.


The objective of this research was to investigate the synergism between ε-polylysine and d-limonene and develop a novel nanoemulsion system by merging the positive effect of these two antimicrobial agents. Results from the checkerboard method showed that ε-polylysine and d-limonene exhibit strong synergistic and useful additive effects against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Saccharomyces cerevisiae. In addition, d-limonene nanoemulsion with the inclusion of ε-polylysine was successfully prepared by high pressure homogenizer technology. Its antimicrobial efficiency was compared with pure d-limonene nanoemulsion by measuring the minimal inhibitory concentration, electronic microscope observation and the leakage of the intercellular constituents. The results demonstrated a wide improvement of the antimicrobial activity of d-limonene nanoemulsion following the inclusion of ε-polylysine. Overall, the current study may have a valuable contribution to make in developing a more efficient antimicrobial system in the food industry.

Keywords: Antimicrobial activity; Nanoemulsion; d-limonene; ε-Polylysine.

MeSH terms

  • Anti-Infective Agents / pharmacology*
  • Bacillus subtilis / drug effects
  • Cyclohexenes / pharmacology*
  • Drug Combinations
  • Emulsions / chemistry
  • Escherichia coli / drug effects
  • Food Preservation / methods*
  • Limonene
  • Microbial Sensitivity Tests
  • Nanostructures / chemistry*
  • Nanostructures / microbiology
  • Polylysine / pharmacology*
  • Saccharomyces cerevisiae / drug effects
  • Staphylococcus aureus / drug effects
  • Terpenes / pharmacology*


  • Anti-Infective Agents
  • Cyclohexenes
  • Drug Combinations
  • Emulsions
  • Terpenes
  • Polylysine
  • Limonene