Oil-in-water nanoemulsions loaded with lycopene extracts encapsulated by spray drying: Formulation, characterization and optimization

Lycopene is very susceptible to degradation once released from the protective chromoplast environment. In this study, oil-in-water (O/W) nanoemulsions coupled with spray drying technology were applied for the encapsulation and stabilization of lycopene extracted from tomato waste. Tomato extract was obtained by ultrasound-assisted extraction. Nanoemulsions were prepared by a high-speed rotor stator using isopropyl myristate as the oil phase and Pluronic F-127 as the emulsifier for the aqueous external phase. The effect of emulsification process parameters was investigated. Spray drying of the produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent. The effect of different coating agents (maltodextrin, inulin, gum arabic, pectin, whey and polyvinylpyrrolidone), drying temperature (120–170 °C), and feed flow rate (3–9 ml·min−1) on the obtained particles was evaluated. Results revealed that the emulsion formulation of 20/80 (O/W) with 1.5% (mass fraction) of Pluronic F-127 as stabilizer in the aqueous phase resulted in a stable nanoemulsion with droplet sizes in the range of 259–276 nm with a unimodal and sharp size distribution. The extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50% during a month of storage time. The most stable emulsions were then processed by spray drying to obtain a dry powder. Spray drying was particularly successful when using maltodextrin as a coating agent, obtaining dried spherical particles with mean diameters of 4.87±0.17 μm with a smooth surface. The possibility of dissolving the spray dried powder in order to repristinate. The original emulsion was also successfully verified.