Changes in volatile, key odorants and bioactive properties of pomegranate juice during processing into concentrate.

Key odorants of juices of pomegranate fruits of Hicaz variety obtained from different juice production stages (fresh: FrPJ, pasteurized: PPJ, filtered: FiPJ, and concentrated: CPJ) were examined. Processing significantly impacted the volatile compounds. The FrPJ and PPJ samples had higher concentrations of aroma compounds than the FiPJ and CPJ samples. A total of 38 aroma substances were identified in the FrPJ sample while 37, 35, and 21 compounds were detected in the PPJ, FiPJ, and CPJ samples, respectively. Phenylethyl alcohol was the dominant key odorant. The total phenolic contents (TPC) and antioxidant activities (AA) of the samples changed significantly. The CPJ sample had the highest TPC and AA due to increased release of phenolics during the concentration process; thus, this process increased the TPC and AA significantly, altering both aroma and bioactive properties. The results emphasize the importance of processing methods in preserving the nutritional and sensory qualities of pomegranate juice.