Ultrasound assisted extraction of bioactive compounds from pomegranate peel, their nanoencapsulation and application for improvement in shelf life extension of edible oils

Abstract

In this study pomegranate peel extract was evaluated as source of antioxidant encapsulated by nano-emulsions in soybean oil. Encapsulating agents maltodextrin (MD), whey proteins isolate (WPI) and complex of maltodextrin and whey protein isolate (MD/WPI) (1:1) were used as wall material. Average droplet size of primary W/O and double W/O/W nanoemulsions stabilised by MD, WPI and MD/WPI were 108 nm, 157.82,189.94 nm and 191.12 nm respectively. Lyophilised nanoemulsion powders were added at 100, 200 and 300 ppm concentration to soyabean and mustard oil and observed for change in various oxidative stability indices during storage and were compared to non-encapsulated extract and synthetic antioxidant BHT. From the results, it can be suggested that nanoencapsulated extract at 300 ppm concentration performed better in controlling oxidative changes in both oils than unencapsulated and synthetic one, however, extract encapsulated by MD/WPI exhibited higher antioxidant effects due to controlled release of bioactive compounds.

Keywords: Edible oils; Lyophilisation; Nanoencapsulation; Pomegranate peel.