Evaluation of antimicrobial activity of macroemulsion and nanoemulsion of Salvia chorassanica essential oil against pathogenic and food spoilage microorganisms

Subject Areas : Food Microbial Contamination

azam mehraban ¹ (Department of Food Science and Technology, Neyshabour Branch, Islamic Azad University, Neyshabour, Iran.)
Mohsen Vazifedoost ² (Department of food science and technology, Neyshabur Branch, Islamic Azad University, Neyshabur , Iran)
zohreh didar ³ (Department of Food Science and Technology, Neyshabour Branch, Islamic Azad University, Neyshabour, Iran)
Mohammad Hossein Haddadkhodaparast ⁴ (Department of Food Science and Technology, Ferdowsi University of Mashhad, Mashhad, Iran)
Masoumeh Mehraban Sang Atash ⁵ (Food Quality and Safety Research Group, Research Institute of Food Science and Technology, Jahad Daneshgahi of Mashhad, Mashhad, Iran)

Received: 2020-08-14 Accepted : 2020-11-14 Published : 2022-03-21

Keywords: Antifungal activity, Nanoemulsion, Antibacterial activity, Essential oil, Salvia chorassanica,

Abstract :

In this study, the GC-MS method identified chemical compounds of Salvia chorasanica essential oil. Then, a nanoemulsions of essential oil was prepared by ultrasound method, and DLS evaluated the stability of its particle size during two weeks of storage at room temperature. The microdilution method investigated the antimicrobial activity of macroemulsion and nanoemulsion of S. chorasanica essential oil against six pathogenic bacteria and three food spoilage molds. The results showed that the essential oil had 20 different chemical compositions. The particle size of the nanoemulsion increased from 91.83 to 193.61 nm during two weeks. The nanoemulsion form of the essential oil had a higher antimicrobial effect than its macroemulsion against all the studied microorganisms. Also, the antimicrobial activity of macroemulsion and nanoemulsion of essential oil on gram-positive bacteria was more than on gram-negative. Among the pathogenic bacteria, the gram-positive bacterium Bacillus cereus indicated the highest sensitivity to the nanoemulsion of essential oil and had the lowest MIC, 3.125 µl/ml. In addition, MIC and MFC of essential oil nanoemulsion against all three molds were determined to be 6.25 µl/ml and 12.5 µl/ml, respectively. Thus, a lower effective concentration of essential oil in the form of nanoemulsion will be required to control food microorganisms and prevent the effects of high concentrations of essential oil.