title: Nanoemulsions of thymol and eugenol co-emulsified by lauric arginate and lecithin.
abstract: Lauric arginate (LAE) is a cationic surfactant with excellent antimicrobial activities. To incorporate essential oil components (EOCs) in aqueous systems, properties of EOC nanoemulsions prepared with a LAE and lecithin mixture were studied. The LAE-lecithin mixture resulted in stable translucent nanoemulsions of thymol and eugenol with spherical droplets smaller than 100nm, contrasting with the turbid emulsions prepared with individual emulsifiers. Zeta-potential data suggested the formation of LAE-lecithin complexes probably through hydrophobic interaction. Negligible difference was observed for antimicrobial activities of nanoemulsions and LAE in tryptic soy broth. In 2% reduced fat milk, nanoemulsions showed similar antilisterial activities compared to free LAE in inhibiting Listeria monocytogenes, but was less effective against Escherichia coli O157:H7 than free LAE, which was correlated with the availability of LAE as observed in release kinetics. Therefore, mixing LAE with lecithin improved the physical properties of EOC nanoemulsions but did not improve antimicrobial activities, especially against Gram-negative bacteria.
authors.affiliation: Department of Food Science and Technology, University of Tennessee in Knoxville, USA.
authors.forename: Qiumin
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Department of Food Science and Technology, University of Tennessee in Knoxville, USA.
authors.forename: P Michael
authors.initials: PM
authors.lastname: Davidson
authors.affiliation: Department of Food Science and Technology, University of Tennessee in Knoxville, USA. Electronic address: qzhong@utk.edu.
authors.forename: Qixin
authors.initials: Q
authors.lastname: Zhong
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D002364:Caseins / Q000737:chemistry; D004655:Emulsions; D019453:Escherichia coli O157 / Q000187:drug effects; D005054:Eugenol / Q000737:chemistry / Q000494:pharmacology*; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D054709:Lecithins / Q000737:chemistry / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000737:chemistry / Q000382:microbiology; D009822:Oils, Volatile / Q000032:analysis; D011492:Protein Hydrolysates / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D013943:Thymol / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D002364:Caseins; D004655:Emulsions; D054709:Lecithins; D009822:Oils, Volatile; D011492:Protein Hydrolysates; D013501:Surface-Active Agents; C026375:trypticase-soy broth; D013943:Thymol; D005054:Eugenol; C031371:N(alpha)-lauroylarginine ethyl ester; D001120:Arginine
keywords: Antimicrobial properties; Essential oil; Lauric arginate; Lecithin; Nanoemulsion