Stabilization of anthocyanin extract from jabuticaba skins by encapsulation using supercritical CO2 as solvent

Anthocyanins are one of most important group of water-soluble and vacuolar pigments in nature. This phytochemical has attracted great interest to the food industry due to the wide range of biological activities including antioxidant and anti-inflammatory activities. However, the introduction of anthocyanins into food and/or medical fields has proved to be a major technological challenge since these compounds have low stability to environmental conditions during processing and storage. In this context, the present study evaluates the encapsulation of anthocyanin extract obtained from jabuticaba (Myrciaria cauliflora) skins in Polyethyleneglycol using supercritical CO2 as solvent and ethanol as co-solvent. For comparison, a conventional method, ionic gelification, was employed to produce encapsulated particles by entrapment in Ca-alginate beads. The encapsulation efficiency of the extract in Ca-alginate beads was higher (98.67%) than those obtained by Rapid Expansion of Supercritical Solution (RESS) process (79.78%). Encapsulated particles made by RESS at different pressures, and temperatures, retained the extracts' biological activity. The best operating RESS process condition for anthocyanin extract encapsulation was determined as 313.15 K and 20 MPa. The degradation studies indicated that both encapsulated systems were more stable to light and temperature than the free extract. Ca-alginate encapsulated Anthocyanin extract release in acid buffer solution was incomplete and slower than when the extract was encapsulated by PEG. Both systems increased the stability of anthocyanin, although presenting different characteristics.

Research highlights► Encapsulation of anthocyanin extract was done successfully by RESS process. ► The best operating RESS process condition was determined as 313.15 K and 20 MPa. ► Ionic gelification process produced higher encapsulation efficiency than RESS process. ► Both encapsulation processes increased the stability of anthocyanin extract.