The effect on phenolic compounds applied some of the procedures during production of pomegrane juice concentrate

Changes in phenolic compounds and other quality characteristics of concentrated pomegranate juice obtained from a production line of a commercial pomegranate juice processing facility were studied using the samples collected from fresh fruits and following several processing steps including crushing, pressing enzymation, clarification, pasteurization, concentration and storage. Color values (L, a, b, hue and C) decreased with ultrafiltration process. Monomeric anthocyanin content was between 242.08-468.56 mg/L however, 28% of decrease in the anthocyanin content was determined following the processing steps. Six anthocyanins including Cy-3,5-diglu, Pg-3,5-diglu, Cy-3-glu, Dp-3,5-diglu, Pg-3-glu, Mv-3,5-diglu and 7 organic acids including citric acid, malic acid, oxalic acid, succinic acid, quinic acid and ascorbic acid were identified and quantified. Total phenolic content of the pomegranate juice was determined between 1760 and 2513.87 mg/L. A total of 15 phenolic compounds were identified in the pomegranate juice and concentrate including gallic acid, vanillic acid, cholorgenic acid, 4H3MSI, 2HSINA, caffeic acid, sinapic acid, p-coumaric acid, quercetin, pyrocatechol, (±)-catechin hydrate, kaempferol, rutin, ellagic acid, syringic acid. HMF content of the pomegranate juice increased 92 % during the concentration process. NTU values of the samples increased during the concentration process and NTU values were found between 51.68 and 60.20 in the concentrated samples during storage. Monomeric anthocyanin contents of the concentrated samples were between 871.35 and 997.27 mg/L during storage. Amounts of the total phenolic compounds of the concentrated pomegranate juices were determined between 17188.80 ? 11965.87 mg/L during storage.