title: Antimicrobial effect of emulsion-encapsulated isoeugenol against biofilms of food pathogens and spoilage bacteria.
abstract: Food-related biofilms can cause food-borne illnesses and spoilage, both of which are problems on a global level. Essential oils are compounds derived from plant material that have a potential to be used in natural food preservation in the future since they are natural antimicrobials. Bacterial biofilms are particularly resilient towards biocides, and preservatives that effectively eradicate biofilms are therefore needed. In this study, we test the antibacterial properties of emulsion-encapsulated and unencapsulated isoeugenol against biofilms of Lis. monocytogenes, S. aureus, P. fluorescens and Leu. mesenteroides in tryptic soy broth and carrot juice. We show that emulsion encapsulation enhances the antimicrobial properties of isoeugenol against biofilms in media but not in carrot juice. Some of the isoeugenol emulsions were coated with chitosan, and treatment of biofilms with these emulsions disrupted the biofilm structure. Furthermore, we show that addition of the surfactant Tween 80, which is commonly used to disperse oils in food, hampers the antibacterial properties of isoeugenol. This finding highlights that common food additives, such as surfactants, may have an adverse effect on the antibacterial activity of preservatives. Isoeugenol is a promising candidate as a future food preservative because it works almost equally well against planktonic bacteria and biofilms. Emulsion encapsulation has potential benefits for the efficacy of isoeugenol, but the effect of encapsulation depends on the properties of food matrix in which isoeugenol is to be applied.
authors.affiliation: iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
authors.forename: Christina
authors.initials: C
authors.lastname: Krogsgård Nielsen
authors.affiliation: iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Kjems
authors.affiliation: DuPont Nutrition Biosciences, Edwin Rahrs Vej 38, 8220, Brabrand, Denmark.
authors.forename: Tina
authors.initials: T
authors.lastname: Mygind
authors.affiliation: DuPont Nutrition Biosciences, Edwin Rahrs Vej 38, 8220, Brabrand, Denmark.
authors.forename: Torben
authors.initials: T
authors.lastname: Snabe
authors.affiliation: Food Technology Division, Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, Kiel, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Schwarz
authors.affiliation: Food Technology Division, Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, Kiel, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Serfert
authors.affiliation: iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark. Electronic address: rikke.meyer@inano.au.dk.
authors.forename: Rikke Louise
authors.initials: RL
authors.lastname: Meyer
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D018441:Biofilms / Q000187:drug effects*; D004339:Drug Compounding; D005054:Eugenol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005516:Food Microbiology; D005519:Food Preservation; D005520:Food Preservatives / Q000737:chemistry / Q000494:pharmacology; D000067030:Fruit and Vegetable Juices / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D005520:Food Preservatives; D009822:Oils, Volatile; D010938:Plant Oils; D005054:Eugenol; C036643:isoeugenol
keywords: Biofilms; Emulsion; Essential oil; Food preservation; Isoeugenol; Spray-drying