Evaluation of the antioxidant activity of extracts from some fruit peels

The growing interest on the replacement of synthetic antioxidants with natural ones has directed many research toward the plant-derived raw materials. The special attention is focused on inexpensive or residual sources from food agricultural industries. Fruit peels are valuable wastes obtained from domestic and industrial sources. The potential of fruit wastes as sources of natural antioxidants was explored in the present research. The peels of five kinds of fruits commonly used were obtained from domestic consumption. Antioxidant activity of their separate extract was assessed using DPPH radical scavenging activity and ferric-reducing antioxidant power. Besides, total phenol, flavonoid anthocyanin, protein and soluble sugar contents of the samples were also determined. According to the results, the apple peel extract contained the most content of total flavonoid, soluble sugar, protein and ferric-reducing antioxidant power. The maximum DPPH radical scavenging activity (256.78 ± 4.54 mg AA. g-1 dry weight = DW), total phenol (13.17 ± 0.268 mg of GAE. g-1 DW) and total anthocyanin (0.811 ± 0.024 mg. g-1 DW) were observed in orange peel. This study demonstrated that fruit peels could serve as potential sources of antioxidants in the food and pharmaceutical industries.