Essential Oils Against Pathogen and Spoilage Microorganisms of Fruit Juices: Use of Versatile Antimicrobial Delivery Systems

• Published in: Journal of food science 2017-02, Vol.82 (2), p.471-476
• Main Authors: Trinetta, Valentina, Morgan, Mark T., Coupland, John N., Yucel, Umut
• Format: Article
• Language: English
• Subjects: Alkanes - pharmacology; Anti-Infective Agents - pharmacology; Antiinfectives and antibacterials; antimicrobial activity; Antimicrobial agents; Candida albicans; Candida albicans - drug effects; Chromatography, Gas; Cyclohexenes - pharmacology; Delivery systems; encapsulation; Escherichia coli; Escherichia coli - drug effects; Essential oils; Food contamination & poisoning; Food Microbiology; Food safety; Fruit and Vegetable Juices - microbiology; Fruit juices; Lactobacillus - drug effects; Lactobacillus plantarum; limonene; Lipids - chemistry; Listeria monocytogenes; Listeria monocytogenes - drug effects; Microbial Sensitivity Tests; Microorganisms; Nanoemulsions; Nanoparticles - chemistry; Oils & fats; Oils, Volatile - pharmacology; Pathogens; Saccharomyces cerevisiae; Saccharomyces cerevisiae - drug effects; Salmonella; Salmonella enterica; Salmonella enterica - drug effects; Salmonella enterica typhimurium; Salmonella typhimurium - drug effects; solid lipid nanoparticles; Spoilage; Staphylococcus aureus; Staphylococcus aureus - drug effects; Temperature; Terpenes - pharmacology
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/1750-3841.13614

Essential oils (EO) are increasingly used as natural antimicrobial compounds, however the effect of delivery system to enhance their antimicrobial activity has not been widely studied. Limonene (0 to 10 μL/mL) was added to microbial suspensions (∼105 CFU/mL) of selected foodborne pathogens (Listeria monocytogenes Scott A, Salmonella enterica Typhimurium, Escherichia coli and Staphylococcus aureus), and spoilage microorganisms (Lactobacillus plantarum, Saccharomyces cerevisiae, and Candida albicans). S. aureus was found to be the most sensitive foodborne pathogen while Salmonella enterica showed continued growth under all concentrations. Stable nanoemulsions and solid lipid nanoparticles (SLN) (d ∼ 170 nm) were prepared using an alkane carrier oil (n‐tetradecane and n‐eicosane, respectively). Interfacial effects and homogenous distribution of limonene in nanoemulsions improved its (8 and 12 μL/mL) antimicrobial effect against S. aureus. Higher aqueous concentrations as a result of expulsion from SLN further enhanced the antimicrobial activity pronounced at higher limonene concentrations. Therefore, our findings confirm that the emulsion‐based delivery systems are able to effectively distribute limonene inside a microbial suspension to improve its antimicrobial activity. Practical Application The use of natural antimicrobials in food products has been gaining attention driven by the consumer preferences. Essential oils (EO) are known to show antioxidant and antimicrobial properties, and can be applied to food products, including fruit juices, to ensure microbial safety and extent the shelf‐life. In this study, we showed that nanoemulsions and solid lipid nanoparticles based on oil‐in‐water emulsions can be used to enhance the antimicrobial activity of EO, and control their release as a function of temperature.