Organic acids and phenolic compounds in pomegranates (Punica granatum L.) grown in Turkey

Thirteen pomegranate varieties obtained from four different growing regions of Turkey were analyzed for their individual organic acids and phenolic compounds in freshly prepared pomegranate juices. Total titratable acidity ranged between 4.58 and 17.30g/L (average of 9.82g/L), and total sugars-ranged between 139.6 and 160.6 g/L (average of 148.75 g/L) in pomegranate juices. According to the results of the z-test for comparison of means, intervarietal differences in total titratable acidity and sugar content of pomegranate varieties were found to be significant within the confidence interval of 95%. Organic acids such as citric, L-malic, tartaric, oxalic, quinic and succinic acids were individually detected and quantitated. On average, citric acid was predominant with a range of 0.33-8.96 g/L (overall mean of 4.85 + 2.83 g/L). L-Malic acid was the second most abundant, with a range of 0.56-6.86 g/L (overall mean of 1.75+/-1.59g/L). Tartaric, oxalic, (-)-quinic and succinic acids ranged between 0.28-2.83, 0.02-6.72, 0.00-0.82 and 0.00-1.54 g/L, respectively. Phenolic compounds identified in freshly prepared pomegranate juices were gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid, o- and p-coumaric acids, catechin, phloridzin and quercetin. (C) 2002 Elsevier Science Ltd. All rights reserved.