Changes in aroma and aroma active compounds during the processing from pomegranate juice to concentrate

In this study, general and aroma compositions of juice samples obtained from Hicaz cv. taken at different processing stages (freshly squeezed, pasteurized, filtered and concentrated juices) were studied. The aroma-active compounds which contribute to the characteristic odor of pomegranate juice were determined by GC-MS-O. Solvent assisted flavor evaporation (SAFE) method was used to extract aroma compounds from the samples. Aroma Extract Dilution Analysis (AESA) was used to identify the aroma active compounds. It has been determined that the processes applied during processing of pomegranate juice into concentrate have significant effects on the volatile compounds of the samples. It has been determined that the processes applied in the study caused a decrease in the amounts of alcohol, ester and terpene compounds in the pomegranate juices and this resulted in the breakdown or removal of the compounds as a rsesult of heat treatment and filtration. It has been determined that the amount of furans in the pomegranate juice is significantly increased by heat treatment. Phenyl ethyl alcohol has been identified as the most potent aroma-active compound. It has been determined that this compound gives rose odor to the pomegranate juices. The total phenolic compounds of pomegranate juices were found to be 401, 657, 470 and 3551 mg gallic acid equivalent (GAE)/L in fresh, pasteurized, filtered and concentrated pomegranate juice, respectively. Antioxidant activity of the juices was examined, concentrated pomegranate juice showed the highest activity consistent with the phenolic compounds.