Evaluation of supercritical CO2 extraction on color stability and antioxidant activity of nanoencapsulated anthocyanin extract of pomegranate peel powder.

In this study, anthocyanin and phenolic compounds were extracted from pomegranate peel powder with supercritical CO2 and Lepidium perfoliatum seed gum and maltodextrin were used as the nanoencapsulation wall. The nanoencapsulation extract was dried with a freeze dryer. Color stability and antioxidant activity of nanoencapsulation extract were evaluated. The levels of anthocyanin and phenolic compounds were evaluated by differential pH and FolinCiocalteu method, respectively. Particle size, nanoencapsulation efficiency of anthocyanin, nanoencapsulation phenol, color stability at different temperatures and pH as well as antioxidant activity were evaluated by DPPH. The amount of anthocyanin and phenol extracted in this method was 3.943±0.133 mg/g of pomegranate peel powder and 504.521±2.537 mg/g of gallic acid per 100 g, respectively. Nanoencapsulation efficiency was higher for anthocyanin than phenols. The release of anthocyanin at different pHs was different, so that anthocyanin behaved differently at different pHs. Polymerization and color increased with increasing temperature. The antioxidant activity of the fine-grained extract by DPPH method increased with increasing concentration and its IC50 was equivalent to 1.092± 0.024 m /ml. [ABSTRACT FROM AUTHOR]