In vitro antimicrobial activity of Spiranthera odoratissima A. St. Hil. essential oils against foodborne pathogens and food spoilage bacteria

Abstract

In Brazilian folk medicine, Spiranthera odoratissima has been used to treat rheumatism, infection and abdominal pain. Essential oils (EOs) are technological options that may be employed in natural foods due to their antimicrobial activities. This paper aimed to investigate the chemical composition and in vitro antibacterial effects of EOs from S. odoratissima leaves and flowers against foodborne and spoilage bacteria Listeria monocytogenes, Salmonella enteritidis, Salmonella typhimurium, Yersinia enterocolitica, Staphylococcus aureus, Escherichia coli, Clostridium botulinum, Bacillus cereus and Pseudomonas aeruginosa. Minimum inhibitory concentration (MIC) values of EOs were calculated by the broth microdilution method on 96-well microplates. Both GC-FID and GC-MS analyses revealed that the major components determined in EOs from S. odoratissima leaves were β-caryophyllene (23.8%), bicyclogermacrene (10.8%) and δ-cadinene (7.1%). Major constituents found in EOs from its flowers were β-caryophyllene (14.1%), spathulenol (8.1%) and γ-cadinene (7.2%). EOs from S. odoratissima leaves and flowers showed strong antibacterial activity against Yersinia enterocolitica (MIC = 0.30 mg/mL), Staphylococcus aureus (MIC = 0.12 mg/mL), Clostridium botulinum (MIC = 0.30 mg/mL), Bacillus cereus (MIC = 0.20 mg/mL) and Listeria monocytogenes (MIC = 0.25 mg/mL). These EOs could be important natural alternatives to prevent bacterial growth in food products.