The distribution of total phenolics, antioxidant capacity, monomeric anthocyanin, and ascorbic acid contents in the peel and flesh of Red Delicious, Granny Smith, and Fuji apples during a six-month storage period were determined. In addition, the effect of 1-MCP (1-Methyl cyclopropene) on these parameters of the edible portion of apples during storage was also investigated. Two different assays were employed to determine antioxidant activities: the spectrofluorometric-based Oxygen Radical absorbing Capacity (ORAC) and the spectrophotometric-based Ferric Reducing Antioxidant Power (FRAP). Total phenolics were measured using the Folin-Ciocalteau method. A determination of monomeric anthocyanin content was also performed using the pH-differential method for Red Delicious and Fuji apples. Antioxidant activity was predominantly observed in the aqueous fraction and was attributed to polyphenolics. Antioxidant activities were highest in the peel, with Red Delicious peel having the highest values, presumably due to anthocyanin pigments. At zero time month storage, the ORAC, FRAP, total phenolics, and total monomeric anthocyanin contents of Red Delicious peel were: 37.7 μmol T.E./g, 62.7 μmol T.E./g, 6.63 mg/g GAE, and 26.4 mg/100g, respectively. The three tested cultivars were significantly different with respect to ORAC, FRAP, total phenolics, and monomeric anthocyanin contents. 1-MCP treatment did not have a significant influence on antioxidant activities and monomeric anthocyanin contents of the three cultivars during storage. Storage did not have significant influence on ORAC values of the edible portion of apple, however it had significant influence on the FRAP values. The contribution of ascorbic acid to the total antioxidant capacity was small. / Graduation date: 2003