Liposomal Encapsulation of Carvacrol to Obtain Active Poly (Vinyl Alcohol) Films.

Johana Andrade,Amparo Chiralt,Chelo González-Martínez

doi:10.3390/molecules26061589

Johana Andrade, Amparo Chiralt + Show 1 more

Open Access

https://doi.org/10.3390/molecules26061589

Copy DOI

Abstract

Lecithins of different origins and compositions were used for the liposomal encapsulation of carvacrol within the framework of the development of active films for food packaging. Liposomes were incorporated into aqueous polymeric solutions from fully (F) and partially (P) hydrolysed Poly (vinyl alcohol) (PVA) to obtain the films by casting. The particle size distribution and ζ-potential of the liposomal suspensions, as well as their stability over time, were evaluated. Liposomal stability during film formation was analysed through the carvacrol retention in the dried film and the film microstructure. Subtle variations in the size distributions of liposomes from different lecithins were observed. However, the absolute values of the ζ-potential were higher (−52, −57 mV) for soy lecithin (SL) liposomes, followed by those of soy lecithin enriched with phosphatidylcholine (SL-PC) (−43, −50 mV) and sunflower lecithin (SFL) (−33, −38 mV). No significant changes in the liposomal properties were observed during the study period. Lyotropic mesomorphism of lipid associations and carvacrol leakage occurred to differing extents during the film drying step, depending on the membrane lipid composition and surface charge. Liposomes obtained with SL-PC were the most effective at maintaining the stability of carvacrol emulsion during film formation, which led to the greatest carvacrol retention in the films, whereas SFL gave rise to the least stable system and the highest carvacrol losses. P-PVA was less sensitive to the emulsion destabilisation due to its greater bonding capacity with carvacrol. Therefore, P-PVA with carvacrol-loaded SL-PC liposomes has great potential to produce active films for food packaging applications.

Highlights

The incorporation of active compounds of natural origin in biodegradable polymeric matrices has been extensively studied as a strategy for developing active food packaging with the ability to prolong the shelf life of foods, through the control of microbial or oxidative degradative phenomena [1,2,3,4,5]
Liposomes obtained with phosphatidylcholine-rich soy lecithin (SL-PC) were the most effective at maintaining the stability of carvacrol emulsion during film formation, which led to the maximum level of carvacrol retention in the films
The lyotropic mesomorphism of lipid associations and the carvacrol leakage occurred to different degrees during the film drying step, depending on the lipid composition of the membrane and its resulting surface charge

Summary

Introduction

The incorporation of active compounds of natural origin in biodegradable polymeric matrices has been extensively studied as a strategy for developing active food packaging with the ability to prolong the shelf life of foods, through the control of microbial or oxidative degradative phenomena [1,2,3,4,5]. Phospholipids are the main constituents of liposomes; their amphiphilic character allows for their self-assembly in an aqueous medium, in which polar and nonpolar regions are driven to align with neighbouring molecules to form favourable interactions, permitting an arrangement in bilayer lipid membranes that generally give rise to spherical vesicles [15,16]. These vesicles can encapsulate the active compounds according to the chemical affinity [17]. Electrostatic repulsion between the particles depending on the charge level and ionic strength of the medium, and their balance with the van der Waals attractive forces determine the particle aggregation kinetics, which affects the protection and release of the encapsulated compounds [20]

Objectives

Methods

Results

Conclusion