NANOENCAPSULATION OF BIOLOGICALLY ACTIVE COMPOUNDS IN A BIOCOMPATIBLE POLYMER FOR POTENTIAL FOOD APPLICATIONS

The production of healthier and more functional food, and safe food storage systems is in constant interest. [1] Nanoencapsulation of functional molecules is an efficacy strategy to increase their solubility, bioavailability and activity, to protect them from degradation and to mask eventual unpleasant taste. [2] The interfacial deposition of the preformed polymer represents a useful encapsulation method as it furnishes polymeric lipid-core nanocapsules (LNCs), which are efficient systems easy to prepare and cheap. These LNCs are formed by the diffusion of the organic solvent into the aqueous phase followed by the solvent evaporation. They have a polymeric wall coated by a surfactant, and a lipid inner core, where bioactive compound is allocated. In this context we prepared lipid-core nanocapsules based on biodegradable and biocompatible poly(?caprolactone) (PCL) with potential applications in the nutraceutical field following two approaches: 1) Nanoencapsulation of active ingredients for potential functional food applications. The approach involves the encapsulation of active ingredients (hydroxycinnamic acids [3] or vitamin E or ascorbyl palmitate) in lipid-core nanocapsules (NCs) based on PCL polymer, coated by a surfactant (polysorbate 80), and an inner core formed by a dispersion of triglycerides/sorbitan monostearate, where bioactive compound is dispersed. The nanoparticles loaded with active ingredients (AI-NCs) showed monomodal distribution with nanometric diameter size, very low polydispersity index (PDI), good or excellent encapsulation efficiency, and stability over time. In vitro tests of simulated gastro/intestinal digestion were performed to obtain useful information regarding the stability of AI-NCs in the different biological compartments. 2) Nanoencapsulation of natural essential oil as potential food preservatives against food-borne bacteria. The approach involves the encapsulation of essential oils (EOs) from Thymus capitatus and Origanum vulgare in PCL-nanocapsules. Differently to the previous approach, the triglycerides in the inner core are substituted by the same essential oil. The EO-NCs showed monomodal distribution with nanometric diameter size, very low PDI, high efficiency of encapsulation, stability and high retention of EOs during prolonged time storage. The antibacterial and bactericidal activity of EO-NCs against food-borne pathogens in comparison with the corresponding pure essential oils were also assayed. References: [1] H. Singh Prev. Nutr. Food Sci. (2016) 21: 1 [2] S. Ranjan, N. Dasgupta, A. R. Chakraborty et al. Journal of Nanoparticle Res. (2014) 16: 2464 [2] G. Granata, G. M. L. Consoli, R. Lo Nigro et al. Food Chemistry (2018) 245: 551