摘要：Bioactive compounds of citrus fruit ( Citrus unshiu ) by-product such as orange and lemon peels extract were investigated. Antioxidant activity of orange and lemon peels extract were compared with BHT and α-tocopherol at different concentrations levels. The highest antioxidant activity of OPWE and LPWE reached to 63.866 and 52.741% at extract concentration 120 mg mL1. Furthermore, antioxidant activity of OPEE and LPEE were maximized to reach to 81.347 and 61.534% at extract concentration 120 mg mL1, respectively. After nanoencapsulation, the DSC showed that the melting point was increased from 73.6-231.8°C for (OPEE) before and after encapsulation, respectively. The TEM showed that the particle size of orange extract was 38 nm before encapsulation and raised a minimum of 4.2 nm after encapsulation and re-dispersion. The encapsulation efficiency of all orange peel extract formulas (10% maltodextrin+2% arabic gum per peels extract), (8% maltodextrin+2% arabic gum per peels extract), (10% arabic gum per peels extract) and (10% maltodextrin per peels extract) were increased to 87.65, 97.62, 63.81 and 72.32%, respectively. Orange peels extract nanoencapsulated (OPNE) characterized with its highest antioxidant potential in all storage period, while the nanoencapsulated of lemon peels (LPNE) gave the lowest antioxidant 52.44% after 60 days storage at 4°C. The OPNE was applied in cake. The obtained cake samples were sensory evaluated. Cake samples showed no significant difference in color, odor, taste, texture and overall acceptability. Finally, the extracts of dried orange or lemon peels could be considered as potential antioxidant ingredients in food products.
