Encapsulation of lycopene in emulsions and hydrogel beads using dual modified rice starch: Characterization, stability analysis and release behaviour during in-vitro digestion

Abstract

The application of lycopene, a potent antioxidant, is limited because of its hydrophobic nature and low chemical stability. To overcome this, different delivery systems, i.e. oil-in-water emulsions and alginate beads, have been synthesized in this study using modified rice starch for improving the stability of lycopene. Lycopene solution (in oil) was used as a control. Modified rice starch was used as it is cheap, GRAS, has better adsorption at the oil-water interface and provides higher resistance to the encapsulated lycopene against the harsh environment of the gastrointestinal tract. During storage at different temperatures (4–70 °C) for 15 days, the lycopene degradation rate was found to increase with increasing storage temperature for all delivery systems and with the type of delivery systems in the following order: solution > emulsion > alginate beads. Further, the delivery systems were passed through a simulated gastrointestinal tract (GIT) model to study the extent of lipid digestion and lycopene bioaccessibility. A positive correlation was observed between the rate and extent of lipid digestion and lycopene bioaccessibility. A significantly higher bioaccessibility of lycopene was observed for the emulsions (20.2%) over the beads (15.6%), whereas the chemical stability of lycopene was found to be significantly higher in the alginate beads (35.6%) than in the emulsions (29.5%). Overall, the results obtained suggest that the modified rice starch can be used as an innovative food-grade material for the design of different delivery systems to improve the chemical stability of lycopene and its controlled release in the gastrointestinal tract.