Characterizing the Novel Surfactant-Stabilized Nanoemulsions of Stinging Nettle Essential Oil: Thermal Behaviour, Storage Stability, Antimicrobial Activity and Bioaccessibility Publisher



Gharibzahedi SMT¹ ; Mohammadnabi S² Show Affiliations
Source: Journal of Molecular Liquids Published:2016

Abstract

Nanoemulsions stabilized with nonionic surfactants (Tween 40, 60, 80) at the different surfactant-to-oil ratios (SORs, 0.25–2.0) were performed and their thermal behaviour, droplet size, storage stability, antimicrobial (minimum inhibitory concentration; MIC) and biological (in vitro digestion extent and bioaccessibility rate) characteristics of stinging nettle essential oil were studied. Thermal stability of the nanoemulsions was studied through a controlled heating-cooling cycle and showed significant differences in their turbidity depending on the type of used surfactant. The Ostwald ripening rate as the main destabilization mechanism at 25 °C was lower than that at 4 °C after 28 days storage, which was in agreement with the Lifshitz–Slezov–Wagner (LSW) theory. The developed nanoemulsions exhibited a much strong antimicrobial activity in particular against Gram-positive bacteria. A significant increase in the lipolysis extent and bioaccessibility rate was found with a reduction in droplet size at SORs ≥ 1.0. © 2016 Elsevier B.V.