Nanoformulation of essential oils, bio-polysaccharides (furcellaran, chitosan) and antimicrobial peptides (RW4, LL37) for application in the food industry - formation, stability and properties.

The food industry is actively seeking innovative approaches to enhance food quality and extend shelf life. To this end, we developed novel micro/nanoemulsion formulations that combine commercial essential oils (oregano, lemongrass, thyme, rosemary) with bio-polysaccharides (cationic chitosan and anionic furcellaran). These ingredients were chosen for their inherent antimicrobial properties, which are crucial for developing new preservation methods. The primary objective was to conduct a comprehensive physicochemical characterization of these novel nanoformulations, which integrate essential oils, polysaccharides, and antimicrobial peptides (RW4, LL37). The interfacial tension measurements indicated the absence of slowly adsorbing, surface active contaminants. The nanoemulsion droplets, prepared via ultrasonication, had sizes ranging from 150 to 400 nm, which appeared to correlate with the essential oils' interfacial tension. The IR spectra analysis supported by the Density Functional Theory computation confirmed that the main components of the commercial essential oils were carvacrol for oregano, thymol for thyme, 1,8-cineole for rosemary, and citral for lemongrass. The negative surface charge determined by the electrokinetic measurements of nanoemulsion drops can result from the dissociation of carboxylic groups at the interface, which could be evidenced by the presence of bands in the region 1700-1740 cm-1. The nanoformulations exhibited stability for 44-60 days, and their potential antimicrobial properties were enhanced by the addition of peptides RW4 and LL37 without impairing the stability. These developed nanoformulations present a promising solution for food preservation applications.