Improving oxidative stability of edible oils with nanoencapsulated orange peel extract powder during accelerated shelf life storage

Nanoemulsion systems were employed to encapsulate the orange peel extract obtained from conventional maceration and novel ultrasound assisted extraction technology. Different wall materials maltodextrin (MD), whey protein isolate (WPI) and complex maltodextrin and whey protein isolate (MD/WPI) (1:1) were used in order to enhance the nanoemulsion stability, protect the bioactive core from degradation and control the release of bioactive compounds. The freeze drying technology was then used to obtain powder encapsulates with encapsulation efficiency and loading capacity of MD, WPI and MD/WPI as 89.3,91.2,95.6% and 95.3,94.4 and 93.1% respectively which depicts that encapsulation has taken place properly. All emulsions obtained were in nanoscale range with average hydrodynamic diameter as 105.0, 201.82, 215.12 and 298.82 for primary W/O emulsion, MD, WPI and MD/WPI stabilised emulsions respectively. These encapsulates were then incorporated in soyabean and mustard oil at different concentration 100, 200 and 300 ppm and compared with free extract and synthetic antioxidant BHT to enhance storage life by controlling the oxidative changes during accelerated shelf life storage at 60o C for 24 days. The results obtained concluded that nanoencapsulated extracts performed better in prevention of oxidative indices than the free extract. However, nanocapsules encapsulated by MD/WPI exhibited higher protection of oils during storage than the maltodextrin and whey protein isolate.