The effect of polymer stabilizers on the stability of lycopene encapsulated emulsions

Abstract

Emulsion-based encapsulation systems are dispersions of droplets of one liquid in another immiscible liquid, and these systems are used to encapsulate both water-soluble and lipid-soluble bioactive compounds. Lycopene is a lipophilic antioxidant, with a highly unsaturated hydrocarbon structure, that degrades when exposed to adverse conditions such as high temperatures, radiation, and oxygen. In this research project, stabilizers such as pectin, xanthan gum, alginate, gelatin and sago were used to investigate the stability of the emulsions. Emulsions of droplet sizes ranging from 300-500 nm were obtained in this study. The antioxidant activity of the encapsulated lycopene containing emulsions was less affected than that of free lycopene. Xanthan gum showed better protection of antioxidant activity. The stability of the emulsion was established by changes in droplet size, percent separation, lycopene content, and antioxidant activity with time. A key finding of this study is that lycopene encapsulation in oil-in-water macroemulsions is effective in inhibiting lycopene degradation, with an encapsulation efficiency of 82-85%. Xanthan gum proved to be the most effective stabilizer and afforded the best protection to lycopene during storage and refrigerating temperature. In conclusion, oil-in-water emulsions stabilized by xanthan gum may afford stability and retention of antioxidant activity of encapsulated lycopene.