P. Paximada, M. Howarth, B. Dubey
Sheffield Hallam University,
Keywords: encapsulation, nano-emulsion, electrospraying, fish oil
Summary:High intake of omega-3 polyunsaturated fatty acids (PUFA) has been proven to decrease health risks in terms of heart disease, stroke, and other cardiovascular diseases. Thus, the development of novel foods enriched with PUFA's is in high demand by the food industry. Their major pitfall, however, is that they are highly susceptible to oxidation. A plausible approach to overcome these limitations is its encapsulation. A wide variety of processes have been proposed to prepare particles 1-3, however, these techniques require heating, damaging the encapsulated compounds. To this regard, electrohydrodynamic (EHD) processing, and specifically electrospraying is beneficial for producing particles entrapping the active ingredients 4. Hence, the aim of this work is to better understand the use of emulsion electrospraying as a one-step preparation technique to obtain fish oil loaded sub-micron and nanostructured particles. In order to achieve this goal, o/w emulsions containing fish oil as dispersed phase and protein (β- lactoglobulin) as emulsifier are being produced. The droplet size of the final emulsions is of utmost importance, as the lower, it is the higher the encapsulation efficiency will be. Taking this into account, emulsions are prepared by high-pressure homogenizer (up to 2000 MPa) and they are further processed by an electrospraying device. The physical properties of the emulsions are evaluated, namely droplet size, stability, structure, rheology. Various physicochemical characterizations of the prepared particles were carried out, including the morphology and size of the electrosprayed particles, and the encapsulation efficiency of the fish oil. In optimised conditions, nano-emulsions were produced (D50 < 100 nm). It was found that the homogenization parameters of the emulsions affect the structure of the particles. Low emulsion viscosity combined with low oil droplet size and high stability yielded particles with the smallest diameters. The proposed emulsion electrospraying technology could be promising for the production of powdered ingredients with enriched omega-3. References 1. B. Dubey, W. Case and E. J. Windhab, in Process-Spray: Functional Particles Produced in Spray Processes, edited by U. Fritsching (Springer International Publishing, Cham, 2016), pp. 941-985. 2. B. N. Dubey and E. J. Windhab, Journal of Food Engineering 115 (2), 198-206 (2013). 3. P. Paximada, A. A. Koutinas, E. Scholten and I. G. Mandala, Food Hydrocolloids 54, 245-254 (2016). 4. P. Paximada, Y. Echegoyen, A. A. Koutinas, I. G. Mandala and J. M. Lagaron, Food Hydrocolloids 64, 123-132 (2017).