pubs.acs.org/JAFC Published on Web 09/10/2009 © 2009 American Chemical Society J. Agric. Food Chem. 2009, 57, 9427–9436 9427 DOI:10.1021/jf901880p Antioxidant Capacity and Lipid Characterization of Six Georgia-Grown Pomegranate Cultivars GARIMA PANDE AND CASIMIR C. AKOH* Department of Food Science and Technology, University of Georgia, Athens, Georgia 30602-2610 Six pomegranate (Punica granatum) cultivars were investigated for their antioxidant capacity and lipid profile. Total polyphenols were determined according to the Folin-Ciocalteau method. Major organic acids and phenolic compounds were analyzed by RP-HPLC. Two in vitro antioxidant assays, ferric reducing antioxidant power and Trolox equivalent antioxidant capacity, were used to assess anti- oxidant capacity. Total lipid was extracted according to the Folch method, and fatty acid methyl esters were determined by GC. Tocopherols and phospholipids were identified and quantified by NP-HPLC using a fluorescence detector for tocopherols and an evaporative light scattering detector for phospholipid analysis. Phytosterols were analyzed by GC. The predominant organic acid was citric acid followed by malic acid. The peel fraction had the highest total hydrolyzable tannins content (4792.3-6894.8 mg/100 g of FW). Overall, the highest antioxidant capacity was found in leaves followed by peel, pulp, and seed. Pomegranate seed had an average lipid content of 19.2% with punicic acid as the predominant fatty acid. Pomegranate seed had high contents of R-tocopherol (161.2-170.1 mg/100 g) and γ-tocopherol (80.2-92.8 mg/100 g). KEYWORDS: Antioxidant capacity; fatty acids; organic acids; phospholipids; phytosterols; polyphenols; Punica granatum; tocopherols INTRODUCTION Phytochemicals, particularly antioxidants from natural sources such as fruits and vegetables, have gained popularity because many epidemiological studies have shown their protective proper- ties against several chronic diseases such as cancer and cardio- vascular diseases ( 1 ). Products and intermediates of oxidative stress pathways are associated with several chronic diseases. Oxidative stress is the disturbance of the pro-oxidant-antioxidant balance in favor of the former, leading to potential damage ( 2 ). Interest in natural antioxidants has increased during the past few decades because of the adverse effects shown by synthetic anti- oxidants and also due to the worldwide trend to avoid or minimize the use of artificial food additives ( 3 ). The most abundant anti- oxidants in fruits are polyphenols, vitamins, and carotenoids. The lipid profiles of several fruits and their seeds have been characterized and various bioactive compounds isolated ( 4 , 5 ). Determination of the lipid classes of the sample may aid in decid- ing its application in food, health, and other industries. This in turn will help in identifying the potential of the crop as a main- stream agricultural product. Pomegranate (Punica granatum), belonging to family Punica- ceae, has been used in several traditional medicine systems. It is a rich source of various bioactive compounds demonstrating anti- oxidant and anti-inflammatory activities ( 6 ). Pomegranate seed oil comprising 12-20% of the total seed weight consists of approximately 80% conjugated octadecatrienoic fatty acids, mainly punicic acid ( 6 ). Highest antioxidant activity has been shown in pomegranate peel compared to pulp and seed frac- tions ( 7 ), which can be attributed to its high content of tannins, especially punicalagin isomers. Pomegranate juice is bright red in color due to its high content of flavonoids and anthocyanins. Pomegranate juice exhibits antiatherogenic activities ( 8 ). Leaves, flowers, bark, and roots also contain distinctive compounds having potent physiological effects. Pomegranate is a minor fruit crop of Georgia, but with the current commercial and nutritional potentials, a detailed study may help in its cultivar selection and application. The peels and seeds, which are usually disposed of as waste material in many food-processing industries, could be a rich source of beneficial phytochemicals. From economic and environment points of view disposing of such wastes should be avoided. Recovery of bioac- tive compounds would help to make the recycling of wastes economically viable and also result in value addition to these minor crops. The main objective of this research was to compare six Georgia-grown pomegranate cultivars in terms of their organic acid contents, antioxidant capacities, and lipid profiles. MATERIALS AND METHODS Plant Material. Six pomegranate (P. granatum, Punicaceae) cultivars, R19, R26, Cvg-Eve, North, Crab, and Cranberry, along with their leaves were obtained from Ponder farm, a University of Georgia operated farm near Tifton, GA. Managed plant growth conditions were minimal. Irrigation was not performed, and only natural rainfall was utilized. No supplemental fertilizers were applied. They were planted in a loamy-sand soil (sand, 86%; silt, 7%; and clay, 7%). Some pruning was performed, but they were not managed in a commercial manner. They were planted from 1990 to 1993 and have been neglected until spring of 2008, when some *Author to whom correspondence should be addressed [telephone (706) 542-1067; fax (706) 542-1050; e-mail cakoh@uga.edu]. Downloaded by UNIV OF GEORGIA on October 21, 2009 Published on September 10, 2009 on http://pubs.acs.org | doi: 10.1021/jf901880p