摘要：In the present work apple peel extracts of (Total Phenols, Flavonoids, and Anthocyanin) compounds from the fruits cultivated in Kurdistan Region of Iraq (BarwariBala mountains in Duhok governerate) are prepared. The three extracts are evaluated concerning the yield and the antioxidant activity of the bioactive compounds by four methods (β-Carotene- linoleic acid assay, reducing power assay, scavenging of hydrogen peroxide, and total antioxidant capacity). The factors affecting antioxidant activity including temperature, pH and incubation time were optimized using Response Surface Methodology. The effect of storage time on antioxidant activity was also studied. The results confirmed that the yield of total phenols were 23.33%, about 31.20 % of the total phenols were flavonoids, while anthocyanin compounds formed 9.76% (g/g raw material). The three extracts showed antioxidant activities of different extents. Response surface analysis results revealed that increasing the incubation time and temperature resulted in decrease antioxidant capacity; however, temperature seemed of top most significant compared to incubation time. The antioxidant capacity of the extracts showed gradual decrease with increasing pH up to pH= 9, followed by an increase towards high pH values. The antioxidant capacity of all extracts were gradually reduced with increasing storage time. The antioxidant capacity of anthocyanin extract was slightly affected by storage time compared to alcoholic and flavonoids extracts. The overall results confirm that the high content of phenolic compounds and antioxidant activity of apple peels indicates that they should be regarded as source of antioxidants.
关键词：Antioxidant activity; Apple peel; Response Surface Methodology
