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.

Formulation, Characterizations and Antibacterial Activity of some Nanoemulsions Incorporating Monoterpenes

“…The latter high energy method characterizes as fast and efficient capable of preparing nanoemulsions with diameters of tiny droplets and distributions of small size (Ghosh et al, 2013). Monoterpenes, the main constituents of plant essential oils, have been documented as NEs to be effective as antimicrobial agents (Ghosh et al,2014;Zhang et al,2014;Zahi et al, 2015;Ma et al, 2016;Li et al, 2017).…”

Food-Grade Nanoemulsions: Preparation, Stability and Application in Encapsulation of Bioactive Compounds

“…One method is homogenizing essential oils in the aqueous solutions containing emlsifier. According to Xue et al and Ma et al, nanoemulsions containing essential oils (e.g., thyme oil, eugenol) were fabricated by directly homogenizing the essential oils in the aqueous solutions containing CS and lecithin, indicating that the antimicrobial characteristics were similar or exceeded those of the free essential oils [172,173]. As reported by Wang et al, eugenol (2-methoxy-4-(2-propenyl)-phenol), which forms a major part of clove essential oil, presents a wide range of antibacterial and antifungal activity.…”

Active gelatin films incorporated with eugenol nanoemulsions: effect of emulsifier type on films properties

“…Additionally, some lipophilic compounds such as eugenol (log P octanol/water = 2.99 at 25 °C) (Griffin et al ., ), have a high vapour pressure (2.96 Pa at 25 °C) (Roon et al ., ), resulting in volatilisation over time and rapid decreasing of its concentration into the active films, principally during drying of the film‐forming solution; thus reducing the eventual activity of the films. Moreover, when applied for food packaging, it can affect the organoleptic properties of the foodstuffs which became unacceptable (Ma et al ., ; Domínguez et al ., ). As well, some added essential oils such as clove oil were found released rapidly from the packaging matrices, without being active for a long time of storage (Đorđević et al ., ).…”