Encapsulation of hydrophilic and lipophilized catechin into nanoparticles through emulsion electrospraying

In this work, we investigated the potential of emulsion electrospraying that contained bacterial cellulose and proteins for the encapsulation of epigallocatechin gallate (EGCG). Specifically, two different catechins, hydrophilic (H-EGCG) or lipophilized (L-EGCG), were encapsulated either on the aqueous or the oily phase of the emulsions in order to compare the antioxidants’ stability. Emulsion properties in terms of stability, droplet size, bulk and interfacial viscosity were studied combined with the evaluation of the properties of the produced particles, namely the morphology and size of the particles, the encapsulation efficiency (EE) of catechin and the stability of the EGCG within the particles under different storage conditions: humidity, pH and temperature. Low emulsion viscosity combined with low oil droplet size and high stability yielded particles with the smallest diameters. Ultrasound homogenization combined with L-EGCG proved to be the most adequate combination, reaching EE up to 97%. The use of low RH (26–53%) and neutral or alkaline pH (6–9) are necessary for protecting EGCG in the particles. All in all, emulsion electrospraying can be used as a promising technology for encapsulation in the food industry.