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 the oil-in-water (O/W) nanoemulsions coupled with spray drying technology was applied for the encapsulation and stabilization of lycopene extracted from tomato waste. Tomato extract was obtained by ultrasound-assisted extraction. Nanoemulsions were prepared by high-speed rotor stator using isopropyl myristate as oil phase and Pluronic F-127 as emulsifier for the aqueous external phase. The effect of emulsification process parameters was investigated. Spray drying of 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 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 stable nanoemulsion with droplets size in the range (259–276 nm) with unimodal and sharp size distribution. 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. The spray drying was in particular successful when using maltodextrin as 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.