Characterization of encapsulated organic pomegranate peel extract powder as a potential natural food preservative

The present study evaluated the influence of maltodextrin (MT), gum arabic (GA) and waxy starch (WS) as carrier agents to encapsulate pomegranate peel extract. Pomegranate peel was extracted using 70% ethanol (PPE) and concentrated to 9% TSS. The concentrated extract was then encapsulated using 10% of the wall materials, followed by freeze-drying (-55°C; 0.1 mbar) to produce the powder. Various properties of the freeze-dried powders were investigated by further analyses of their physicochemical, techno-functional, phytochemical and antioxidant properties. Results obtained for each parameter investigated were significantly different (p<0.05) among carrier agents. GA presented the highest solubility percentage (96.63%), hygroscopicity (10.97%) and TSS (9.33). Waxy starch had the highest anthocyanin retention potential (25.17 mg C3gE 100 g^-1 DM), followed by maltodextrin (11.02 mg C3gE 100 g^-1 DM) and gum arabic (8.88 mg C3gE 100 g^-1 DM), respectively. FRAP activity was high for powders produced with gum arabic (89.97 mM TE g^-1 DM) followed by waxy starch (82.43 mM TE g^-1 DM) and maltodextrin (64.03 mM TE g^-1 DM). Maltodextrin had higher (72%) encapsulation efficiency compared to gum arabic (61%) and waxy starch (37%), respectively. Overall, this study showed the combination of gum arabic and maltodextrin as more suitable carrier agents for encapsulating pomegranate peel extracts as a food preservative.