Improvement of Antioxidant Activity and Physical Stability of Chocolate Beverage Using Colloidal Cinnamon Nanoparticles.

In this study, the functionality of colloidal cinnamon nanoparticles in improving the antioxidant activity and suspension stability of a chocolate beverage formulated with two types of cocoa powder (natural and alkalised) was investigated. Cinnamon-loaded nanoparticles based on shellac and xanthan gum prepared using anti-solvent precipitation were incorporated in the chocolate beverage in multilevel proportions. The results showed that the addition of the nanoparticles improved the total phenolic content up to 40% and antioxidant activity up to 60% depending on the level of the nanoparticles added. Improvement of the physical stability of the chocolate beverage was observed regardless of the cocoa powder type. As the sedimentation index of the beverages made with alkalised and natural cocoa powders after 96 h was 5.7 and 85.7, respectively, the stabilisation effect of the nanoparticles seemed to be significantly influenced by the characteristics of the beverage raw material. The prevention of cocoa particle sedimentation was attributed to the colloidal network that originated from xanthan gum as shown by Cryo-SEM imaging or the increased viscosity of the mixture (i.e. from 2.4 to 27.7 mPa s at a shear rate of 50 s−1). Incorporation of the colloidal cinnamon nanoparticles had no significant effect on pH and a slight effect on the colour of the chocolate beverages. The formulated nanoparticles could be a promising complement to "ready-to-drink" products to enrich the bioactive content and prolong suspension stability. [ABSTRACT FROM AUTHOR]