Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 3 10 2015 12 3 Apple Peel is a Promising Source of Natural Bioactive Compounds That Promote Human Health 624 628 EN Sercan Karav Department of Food Engineering, Ankara University, 06110-Diskapi, Ankara-TURKEY Ardic O. Arikal Aziz Eksi JFNR20153101 10.12691/jfnr-3-10-1 2015 8 10 2015 10 22 2015 12 1 Antioxidant capacities (AC) and total phenolic content (TPC) of sixteen apple varieties obtained from different regions of Turkey and six commercial apple juices were examined. Trolox Equivalent Antioxidant Capacity (TEAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assays were used for AC measurement while Folin-Ciocalteu method was applied for TPC measurements. 'Ankara Agustos' cultivar showed the highest antioxidant capacity (7.60 µmol TE/g FW) followed by 'Bursa Gloster' (3.10 µmol TE/g FW), and 'Antalya Red Chief' (2.90 µmol TE/g FW), whereas 'Antalya Granny Smith' exhibited the lowest antioxidant capacity (1.50 µmol TE/g FW). AC's of commercial apple juices were found to be 2.8-fold less than the average of naturally produced juices with range of 0.38-2.56 µmol TE/g FW. Total antioxidant capacity changes at 4°C over time were also monitored for three varieties. A significant decrease in total antioxidant capacity after five weeks was observed. Moreover, the high correlation between AC and TPC of naturally produced apple juices (R2>0.97) indicated that phenolic compounds are a major contributor to the antioxidant activity of apple fruit.