Essential oils application as Bacillus cereus antispore agent in food hygiene

Abstract

Adherence of Bacillus cereus spores to dairy industry equipment is a serious problem, causing food spoilage and, occasionally, outbreaks of foodborne diseases. Antimicrobial essential oils (EOs) have been proposed as an alternative to synthetic disinfectants due to their environmentally friendly properties. The aim of this study was to assess the effect of Cymbopogon winterianus and Juniperus phoenicea EOs on planktonic and adherent B. cereus spores to stainless steel surfaces. Eleven strains of B. cereus were used in this study. The chemical composition of the C. winterianus and J. phoenicea oils was analyzed by gas chromatography (GC)/mass spectrometry (MS). Ninety components were identified for C. winterianus, being geranial (37 %), neral (29 %), beta-myrcene (16 %) and geraniol (4 %) the most abundant constituents. Twelve components were identified for J. phoenicea, being alpha-pinene (65 %) the most abundant constituent. The results of the minimal inhibitory concentration and minimal bactericidal concentration revealed that C. winterianus was the most effective EO (p < 0.05) against all eleven strains. In addition, there was a large log10 reduction (from 4.93 to 2.42; p < 0.05) between spores in planktonic form versus spores adhered to stainless steel surface. C. winterianus can be used for effective detachment of B. cereus spores capable to adhere and form biofilms on stainless steel surfaces, being a valid alternative for the development of natural disinfectant that may reduce negative effects of synthetic chemical disinfectants.

Keywords

• Bacillus cereus
• Java citronella
• Juniper
• Essential oil
• Bacterial spores
• Stainless steel